No affirmative words from boyfriend

Hi,

My boyfriend and I have been together for only about six months and his interest in me, but especially the way he shares love verbally has highly decreased. I seldomly experience warm, affirmative words from him anymore and every attempt to talk to him about it becomes defied, either logical arguments or silence. He has his own issues too, suffering from low esteem/self consciousness and being very hard and critical on himself. I often have the feeling he might slip into depression (again) and that my dissatisfaction about how things are between us lately might make it worse. At the beginning I was dazzled with his loving words and high interest in me and even romantic actions. Now it's like we live in an igloo emotionally at least on his part. I even asked what he actually wanted or if he wanted to break up but he said 'he'd rather not'. Moreover, we live in a long distance relationship atm where good communication is essential and loving words are part of my emotional needs. I make no secrets of communicating my needs and emotions and I need to talk through issues but he becomes more and more closed off.

He makes me feel not good enough for him and unloved like the critical, hysterical hen, the antifeminist stereotype. Well, at least from the distance. I've to admit we get along better when we're actually together although last time it has already felt a little off or clumsy, not as super happy and loving anymore. He says relationships just change over the time, that it's a natural development and he's never been the one to share a lot of emotion. Yet sadly I vividly remember the difference - which is not part of my imagination but there's evidence in texts and other things that it was different before. I feel misunderstood and rejected.

This development worries me very much and I hope to find some words of advice, understanding here.