Me (23M) and my girlfriend (22F) have been together for almost 2 years. In the first year of our relationship the sex was great, she didn't (and still doesn't) want penetrative sex, which I am perfectly OK with, but we used to do oral and hand stuff everywhere, at home, outside, at the library etc.
We never got caught doing it but we did get caught kissing a few times, and we live in a rather conservative neighborhood so some people did actively show their discomfort at us. This affected my girlfriend as she now doesn't even want to kiss when we're not home. This is perfectly fine too.
I was always the hornier one in our relationship, and there were times where she didn't want me going down on her. She quickly learned what I like and how to give me a good blowjob. But since she didn't want me doing it that often I never fully got what she likes and I've never been able to make her cum. I've done research, I've read books, I asked her during and after sex. I learned a lot but it wasn't enough. We had some problem with this since it made my confidence plummet, but she said she's fine with it and that she's "hard to please anyway". I know she's telling the truth because 1) she's my girlfriend and i trust her with everything and 2) a more tangible reason, she actually cried happy tears once, after I went down on her. So I know even though it isn't enough to make her orgasm, she still likes what I do.
Fast forward to now, we're at a time where our college work is harder than it ever was. Once every two week is exam week and she said she never wants to do it in an exam week because it's already stressful. She doesn't even want to have long kisses if I'm the one initiating it because she thinks I'm gonna want sex and when I try to kiss her she just backs off even though I never said anything about expecting sex after initiating a kiss. But sometimes she doesn't even want to do it even in a non-exam week (which is again, perfectly fine, she doesn't owe me sex, and sex is done with both sides' enthusiastic consent) but sometimes she says she wants to do it, she gives me a blowjob, and when it's her turn she says she's done and doesn't want to do it anymore. It honestly leaves me feeling confused and "handled" (if that makes sense), like she's just giving me a blowjob just to get it over with and she doesn't want me going down on her. She likes it but doesn't want it? I'm the one getting pleasured but it doesn't feel right when it's done like that.
The "not having much sex" and "backing off from a kiss" things make me sad on my bad days, yes, but the thing where she just does me and doesn't want anything done to her makes me feel even sadder and honestly plain confused.
We've had some talks about this, some were civil, some were more fight-y, and I feel like I killed her sex drive with all these talks.
What am I supposed to do to improve our sex lives and make my girlfriend feel more at ease around me?
TL;DR: My gf rarely wants sex, sometimes backs off even from kisses. Sometimes she gives me blowjobs but doesn't let me go down on her. She said she likes me going down on her but her actions are saying different things. I am not happy that I am the only one getting pleasured because it doesnt feel fair.