Re: 20 years old and having issues in bed.
I have had the same problem with a girl I've been sleeping with recently, I get aroused during the foreplay but when it comes to sex I something kicks into my head we're about to have sex and I start going soft, and as for condoms, I've halfway down by the time its out of the packet, thankfully we've been able to have sex without condoms, but as you pointed out, I shoot quickly, due to worries I won't stay hard during sex and also because I guess I'm very sensitive. So yeah it would be nice to be hard after the build up and naturally progress into sex without thinking about it and therefore my mind being free of worries, I can enjoy the sex and it would probably last a lot longer also.
Good luck with finding answers, I'm hoping for me, experience will help out and be less worried about sex and it being less of a big deal. Could this possibly be the reason things happen to you? Is having sex a really big deal?