Me(30m) and my partner (27f) havent had sex in 8 months

our sex life was consistent and great for 4 years. once things slowed down, they quickly came to a halt. for the first month she would deny that the DB was happening. then the second month she’d get angry and confrontational when i would try to express my concerns. the third month she calmed down and admitted something was wrong, but didn’t know what. she is bipolar and recently stopped taking one or two of her prescriptions which could be an understandable contributor. the fourth month she admitted to me she holds some resentment towards me for not being there for her at a time she needed me last year. said she loves me dearly and wants to get through it. I feel like i spent the next 4 months watching all affection, attraction, and interest slip away as my frustration quietly tears me apart.

we had planned on moving back to our hometown area about 1000 miles away, she decided to go there and stay with her parents until we found a place, ive visited 3 times, feeling less love each time. she knows its hard for me and says shes trying to work it out. she wont speak to me about it though. and honestly it looks like its not even a concern of hers anymore. she has a very hard time communicating anything thats bothering her, even just to herself.

but after some time alone she told me she was ready for me again and we should celebrate with a romantic trip so we went on a nice vacation for valentines day. but nope. nothin. it really fucked me up. i love her and just want to get this issue solved so we can be happy again. she bombards me with loving words, as its the most she can do lately. but this is getting very hard for me.

I told her I’d come back for her birthday. which is very soon. but a month went by since we made those plans and as i sat down to buy a flight i was consumed with anxiety about experiencing another 2 weeks with her without an intimate connection. my head is spinning, i dont know what to do. i’m contemplating telling her that after the hurt i feel from how our valentines trip went, i dont think i can come up there again if we cant be intimate. i feel so defeated and lost that i cant tell at all if thats the right thing for me to do.

i feel pretty bad with the thought of slapping her with that just days before her birthday. and im not very confident that i want to say that at all. i dont want our relationship to feel like were just friends. but i love her and believe she loves me and i do in fact want to go up there and spend her birthday with her like we planned months ago. but somethings telling me that maybe i should say that. i cant tell, it feels like a selfish and certainly counterproductive sentiment towards encouraging any chance of intimacy. but its to convey that i dont know if i can willingly put myself in a position of feeling that pain again. maybe i should just not say anything of the sorts and try to have a good time with her on her birthday and depending on how those two weeks go i can take it from there.

Now in telling her that I wouldn’t word it like that or use it to pressure her, it would be reasoning as to why im not flying up.

it just feels so wrong to cancel last minute, and to do this right now. ah i cant think straight.

any advice? thank you.

tl;dr: should i cancel flying up to see her because our lack of intimacy is causing me to contemplate ending our relationship?