First of all, thank you for ignoring the fact that I'm stil in high school. But that's neither here nor there
True, sex can affect how you view a person (but I disagree on some level

). My girlfriend is also a VERY sexual person and it's hard work, at least on my part. I don't mind the work, though, because in the end she's happy and I couldn't be more pleased.
Well, you can't just blurt out "Why do you come so quickly." Especially without a warm-up in the conversation. you have to mention it preferably in conversation about both your performances in bed. He might have something he wants to tell you. You never know. And whether he's talked to a buddy about it or not he HAS to have thought about it at least once. Like I said, it's a very sensitive issue for guys. Just be open with him. Trying to fix this problem as couple will benefit your relationship.
This problem will not last forever. I was actually just reading another forum about this and it should pass with 'time and experiennce'. Do your best to be patient with him. He'll appreciate it and will work harder to deal with this even more.
And if the condoms do work then you won't have to worry about your ex being in your head anymore because you'll be to busy thinking of how long your boyfriend has been inside you. My girlfriend tells me that she loses the ability to think. All she does is scream, pant, and squeeze anything she can grab ahold of.
Once things seem to be getting better than start doing kinky things that will tend to your sexual inner self. Trust me, you'll feel so sexy and you'll turn your boyfriend on so crazy he's going to want to eat you (not actually eat you haha you get my point). for my 18th birthday, my girlfriend picked me up, blindfolded me, took to a hotel, sat me down, wore the sexiest see through lingerie this world has seen, and pleased me like the good Lord intended a man to be pleased. she said it was just as satisfying for her as it was for me.
Yes, be willing to try the numbing rubbers haha. It will help.
Peace and Love,
Jorge