Any insights on the negative feelings that come with caregiving?

I feel so nasty asking this, but I’ve accepted it’s a natural thing to feel. How can I not become resentful? I hope this doesn’t come off as selfish or too negative. I don’t WANT to feel this way. I want a positive perspective, but life has been so hard I struggle to stay positive. I’m bipolar and pregnant and I’m taking care of my schizophrenic partner in the midst of the worst episode of their life. I was more than happy to help in the beginning, but life really started getting stressful. My lease with my roommate was up in July and I had to find a place for my partner and soon to be baby within my budget. They obviously can’t hold a job right now. I was so stressed that I became suicidal for a few weeks. Once we moved in together it got better. But now I’m becoming resentful. It’s minimal, but it’s enough to scare me. I’m starting to get annoyed with the constant attention and help they need. I just keep thinking “when will I get a break?” “When will things be about me?” I expected pregnancy to be this beautiful spiritual experience, but overall I can’t say I’ve really enjoyed it. I think it’s mostly given my circumstances. I almost feel like I’m mourning the idea I had of it. I truly love my partner and our relationship is very healthy and open. There are no harsh feelings towards them, just their illness. I feel capable of continuing to help them and take care of them. I just am starting to become distant romantically and they are already catching on. I don’t have friends really and finding therapy appointments when I work 8-4:30 and already have OB appointments is hard. I’m trying to do more self care and have more alone time, but it seems it always ends with them coming to tell me they feel bad and need help. My mom keeps telling me I can’t put this much stress on myself, especially while i’m pregnant, but it’s like what can I do?