My partner seems to only enjoy eating me out when I'm on top

My partner and I (20M/21F) have been dating for a little over 2 years now, and we have been getting intimate since the beginning. I was self conscious about them eating me out, but they wanted to try so we agreed and I actually enjoyed it too. I'm still self conscious about it, I won't let them do it if I haven't showered, shaved/trimmed, or at least had a chance to clean up in a bathroom.

They always talk about how much they love going down on me and how enjoyable it is for them, but they don't really do it that often? If I ask they'll do it for a few minutes and then we switch and I finish them off. It's hard enough to orgasm as a woman, but it feels like they don't really enjoy doing it, but say they do so I don't feel bad about myself.

My partner has wanted me to sit on their face since the beginning, and me having so much self doubt have been apprehensive about it. I didn't want to do it at all because I didn't want to hurt them or fuck something up. But a few weeks ago I gave in and suddenly my partner was REALLY into it. But then when it came back to just doing it normally because I got scared, it went back to only wanting to do it for a few seconds before moving on to having sex.

How do I address this? I don't want to accuse them of not enjoying it and have it make things awkward because I misunderstood the situation, but it hurts feeling like they don't really enjoy going down on me despite all of the talk about it.

TLDR: I think my partner doesn't actually like going down on me unless I'm sitting on their face, which makes me uncomfortable and hurts a little bit.