Realizing this may be an unpopular opinion: talk to him about it. If you're comfortable enough to have his penis inside you, you should be comfortable enough to talk about the sexual issue. Acting like everything is A-OK is just going to make it worse. Communication is absolutely key.
Of course, you kind of have to meet each other half way. You may have to settle for him only being able to ejaculate once (in my experience, that's all most men can do within an 8 hour time span), or experiment more with other sexual activities to ensure that you're both satisfied. By the same token, he may have to work on the premature ejaculation issue. If things don't improve after you've addressed the issue, then I would definitely break up with him (sex is important to me), but I can't advise you to expect this man to be a mind-reader. That would be unfair.
Sexual compatibility is VERY important, but it's nigh on impossible to have a healthy relationship without that communication. If you want to read more about this issue, you should check out the livejournal community --
Sextips . Generally speaking, though, the consensus there is the same as mine here: if you don't talk about it, you'll never be able to fix it, and old habits are hard to break.
And realizing this is random: most people suck in bed the first time, LOL! It's because everybody likes different things, and you aren't used to each other's likes and desires yet...that doesn't really fit with this situation, but you said you expected it to be "mind-blowing" the first time, so I thought I'd throw that in there.