Boyfriend feels sick during sex?

Hi guys,

My boyfriend is 21 and is fairly healthy. He recently started going through a rough time dealing with random bursts of depression and just stress. During this time it has also impacted our sex life. I would t say im “horny” most of the time, but being a young female on birth control i can say that I would be down to have sex! Recently however, i feel like i always have to wait for him to make a move because he isnt in the mood until right before we sleep. Which is okay but he used to always appreciate getting some (and he would initiate it which would make me feel good about myself). I respect the fact that he doesn’t have a high sex drive anymore and I have gotten past thinking it was my fault. Now, we have another situation. The first time this happened was over a month ago but he got so sick right after he finished. He got dizzy and nauseous and honestly turned grey. That was the worst one he has ever had. Before and after that incident he would feel nauseous and faint during sex and he’s never had that before. The other day we started having sex after a week of not having it because we had guests, and he asked to stop shortly after we started and proceeded to feel very uneasy and “sick” again. He says hes kind of nervous to have sex again because then he feels awful for the rest of the day.. i swear this isn’t normal and it makes me so upset since we are so young. Idk if this is psychological and he just gets so excited his body doesn’t know what to do or if theres slmething else going on. Please lmk