Should I stay and try or leave and start over

Hi, I am new here. Still not sure this will help, but I think it's forth trying.

The issue I am dealing with is in my perspective complex, because there a few things overlapping and which have been developing for some time now.

I have been with a man for almost 4 years now and until last October or so we have been happy. Within last 2 years we have been travelling a lot, with him travelling even more for work as he is an academic on constant research, which he loves and it's essentially his lifestyle. Last summer we arrive to a new place, where he secured a great and dream come true position at the university which he's been very happy with. I, on the other hand, left my career in another country to pursue a new one, with a gap year spent on studying my topic and networking internationally. Overall, I had less luck in securing a good position, or position at all, apart from occasional remote gigs for few organisations, so for me it has been a career roller coaster. With last gloomy winter in the Northern hemisphere, no network in the new country and no real job, it wasn't hard to get anxious and depressed. I think I actually got seasonal depression. Now, while soaking up the summer sun, things look brighter, so that's how I know it wasn't, well, serious. Nonetheless, rather unproductive.

It's not hard to imagine, that with settling in and no travelling as a distraction, the reality and unresolved issues kicked in.

1. I don't feel comfortable around him. I think it started long time ago, but it only kicked in fully last winter. His ego. the fact he keeps talking about what he does, whom he met (promising to introduce me to all of his new colleagues, of whom to date, I might have seen only few); not asking about how I am, or asking just superficially, to return to his stuff with the next round; interrupting; mocking (rather silly, but annoying), correcting me, mansplaining (might be just an academic default, but still toxic). I can go on forever. Point is, that, at some point this bitterness over little pinches spilled out and I started to get angry with him. Funnily enough, there has to be a glass of wine involve. He reads these kind of situations as me trying to fight. I guess I am. And that is because:

2. We haven't really talked deeply, with care and understanding for a very long time. Maybe last spring it was when we had good time and actually connected. Now he brushes off any request for discussion as a potential argument. Yes, he avoids conflict to the point, when he pretends I don't ask 'difficult questions' or changes the topic ... I asked him recently to help me with that as there are obviously things not going well - he dismissed me saying that he doesn't want to talk when he is tired, or in a good mood. Avoidance of course. I just don't know where to start or what to do. I asked him to tell me when he is ready to talk seriously as I feel there is a need for it. No answer. One of these deeper issues is that I caught him recently on ...

3. Chatting to his colleague. Female of course. She's been around for a while, so I know there was something off, when he invited her to few projects (written output) but equally to a few conferences (she wouldn't gt there without him) of which last (recent) she attended with him. I was furious. What's even more crazy, he cut off comms with me, something we used to do while he was away on daily or almost daily basis, if I wasn't actually attending the conference myself. We spoke after he was back and I literally asked him what happened and whether he cheated on me. He denied and said he needed time and space to think (never told me about what though). Well, perhaps. Trouble is he also parties a lot, especially at conferences. He doesn't seem to be the who would quickly fall for someone, but he does get flirty while tipsy. He did say, he wants to be with me, but it sounded like sth actually happened between them, after which he decided he is better of with me ... I am still considering meeting her, but since I have no hard evidence, this might be uncomfortable and could bite me in the end as the network here is pretty chatty. That was also (after few drinks, when he admitted he was considering/tempted by her as a successful scholar, working in the same discipline. I can see how perfect couple they would be.

4. The proposal - some time ago (February or so), while having great night in with good food and, again, wine, he just asked me if I would marry him. I actually remember asking next morning whether he had been serious, because there was nothing about it that would make it somehow special. That's right, no ring, no I want to talk to you, no sweet talk. I still don't know what to think about it especially, because, while we were trying to clarify the air after the conference with a colleague, he reminded me about the proposal and said: 'you didn't do anything about it, you didn't act on it' as if somehow it was my obligation to start frantic wedding preparations. We are from cultural background that are rather nontraditional, we especially if we're talking about male/female duties, so I was a bit surprised to hear that. I do remember asking him about what kind of ceremony he'd like to have and I reiterated the question recently, but I didn't get any answer. Which brings me to the last chapter of the saga:

5. He says 'I love you' and 'I want you to be happy' while suggesting I should take that few month assignment in another country, as he wouldn't mind spending winter somewhere else. Perhaps, he could ask me first what makes me happy and how he could be a part of it ... Well, but that would unleash all the demons of deep conversations ... something he's dreadfully scared of. So he avoids the hard sh*t again.

6. Small things follow: we don't talk that much or at all about anything, though we stated we would like to talk about our future here where we are now (potentially for few years), he wants me to have a career that he could be proud of (well, me too) but is seriously unsupportive when it comes to pass my contacts in the very tight network we live in; He feels I am entitled because I live of his money while trying to get a job in my sector (which is scarce here), he wants me to have more friends and do things separately as well as together (that's after I the female-colleague drama); I don't have friends here, some acquaintances, but nothing serious since I haven't been here for that long; since I have been travelling of the last 7 years, my other friendships faded away, so I don't really have many people around me now; which i a problem for him, because he feels I am hanging on him (which might be true) and it doesn't make me feel great emotionally so I am spiraling into some dark moments when I imagine, he is secretly pushing me away to avoid a big drama and break up with me while I am away.

So, my question is: am I going mad? if so, what shall I do? Get a therapist to heal my insecurities? Can I save this relationship (after all we were happy for 3 years) and if yes, how? Is there any hope for the avoidance and lack of communication? How to talk him into that? Or shall I just start making exit plans, while enjoying nondramatic erosion of what's left of the once great relationship.

Thank you for reading and replies.