My gf and I, we see each other each week during the week-end, spend 1 or 2 night together, we never have sex in the morning, only before going to sleep, and not every time. Sometimes she is just tired or idk, but when I am, I'm still wanting her, wanting to have sex with her. I'll never force her to do anything and I don't want her to act like she's wanting to have sex when she doesn't of course. But even when we have sex, we do foreplay (I essentially do everything) then we fuck (I still do essentially everything) she enjoy it, but she's not really "active". I always initiate it, and she end it, because I have difficulty cumming, she'll cum maybe 0,1, or multiple time, then feel tired or bored or not excited anymore (This is the main reason she puts forward), and after ≃ 5/15min of penetration end it.

I don't understand her, and she don't really like to talk... So I really don't know what to do, to please her and please myself. Do you got any advice about this situation?