Make the emotional build-up slower and less sudden.
Leave the cutting out period.
Make the emotional content more fulfilling, reachable, realistic and understandable. You want your readers to be able to feel what your characters feel, to be able to empathize with those emotions whether good or bad. When it's distilled down the way you have it, the reader can't immerse themselves in that experience. You want deep, yet simple. Rational, yet as irrational as most humans are at the core.
As for the sex, I would have left that until later in the story, possibly after a slow build-up that took weeks, perhaps months. You do have talent, you just need polish and experience.
Author's response
Thank you for your suggestions. I'll keep them in mind.
I'm definitely not going to leave the cutting out because this story was a way for me to get out all the emotions I've felt over the years while I've been struggling with it. A lot of people do relate to that. It also raises awareness of the issue.
I've always felt that the sex came too soon. I wrote this years ago though, and while I'm changing how scenes go and everything, I feel it would just take too much time for me to change that right now. It's also such a major change. I have finals the next two weeks so I might decide to change it, but it will be after that if I do.