Me and my girlfriend/fiancee(17, then 1 have been together for 10 months now. We've been having sex for 9 months. We were both virgins and kicking it really good, we've had sex almost everyday. It was good, at first. Then she got pregnant while she just finished her pill. After she was pregnant, we had a little bump, but we didn't let it get in the way of us having sex. We continued to have sex while she was pregnant, and it was good. 3 months after her pregnant, she and I decided we weren't fit to be parents so we had an abortion, (because we would be too emotionally attached to it if it were born.) and for some reason it didn't really affect our sex life.. We continued about 3-4 weeks later. She got back on the pill, she changed the pill once more because it gave her zits.
Anyways, to the point.
We have sex still, an awful lot. Sometimes 2 to 4 times a day. Sometimes just once. And the only thing that really gets me off is Oral sex. She has to get me really close to climaxing with a blowjob or a handjob so that I may climax inside her (I have to be at my peak, it helps her get off.)

I used to love having sex.. And I admit. I do masturbate still, a bit too much, when she's not here. I'm trying to cut back on it, because I've been reading around here...
She asks me to shave, and after I shave, my balls get loose. I heard if they're not firm, you can't ejaculate if they aren't firm from what I understand. And my balls just won't get firm.


Really, I can't stay erect long enough to please myself, much more, my girlfriend. So what do I do about it?
What should I stop in order to be able to get off again? I've had the same habits for months, why is it effecting me now?
Before this happened, I had really good, surprising, large erections, and now it seems like I can't even have one anymore.. Please. Help!