Please Help Me

I've got a big problem. I can't hold down a boyfriend for longer than two weeks. Meeting a guy and getting him to date me is easy, I'm pretty enough, but having him stay with me is a whole different story. I get so excited when I meet a guy, touching his hand, smelling him when he is standing next to me, it excites me so much sexually that it feels like foreplay, and then when we get into the bedroom, the moment it goes inside of me I orgasm and it's over, and I mean totally over. I feel so sensitive after my orgasm that I can't possibly go on and satisfy him. Guys are starting to think that I'm selfish, sexually, and even though I've been dressing so much sexier to attract guys, they are steering clear of me...until I met John. I'm playing it different with John so I'm holding out with having sex with him until this week. I know I have a premature orgasm issue (they call it PFO actually, it's a real condition called Premature Female Orgasm). I thought that if I waited much longer, a lot more dates with a guy, then the excitement would wear off, and I could concentrate on enjoying sex, more than sex, I want to be fucked really hard and long. John and I have been sleeping together and my condition is the same, two pumps and I'm done. I start to think that I'm "done for," that I'll never ever have a boyfriend or a husband, and I'll be an old maid for the rest of my life. My sweet brother knocks on the door. I get the idea to play house with him. We used to play house when we were young. We would pretend we were husband and wife, rubbing our bodies together with our clothes on. Back then, it felt good, natural, and exciting! He’s going to help me! He’s going to coach me. I know how to seduce a guy, it’s easy, but will seducing my brother with my condition be easy?