<human>: For the last few months whenever my GF or I visit each other, she has been avoiding us having sex. Sometimes she says she is in too much pain, sometimes she's upset or not in the mood, and the few times we do have sex she stalls a lot, talks or jokes about nothing, acts very weird, and even worse will put forth absolutely no effort to the point where I completely lose interest as well. The only time we actually have sex, she's very drunk.

I have no idea how this started, I've tried to talk to her about it and basically she doesn't know or is refusing to tell me. I don't know how to deal with this and it's putting a huge strain on our relationship. Please any advice would be appreciated.

Can you condense the text into a few key points?
<bot>: GF doesn't want to have sex anymore and I'm still horny. And it's putting a huge strain on our relationship.