He cums in less than 10minutes and doesn't make it fun for me
The basic thing he has to learn is to spot the signs that he's about to come and then, if he doesn't want to do so just then, lessen the stimulation so that he doesn't. The fact that he can last five minutes says that, if he learnt this, he could do fifty or any other time.
Have a read of Bernie Zilbergeld's 'Men and Sex' or 'The New Male Sexuality' - amongst dozens of them, there's almost always a listing on Amazon of one of them for 1p + postage second-hand. Amongst much else, it has a good programme on how to learn this.
Maybe find a way for him to get you off before he does.
Maybe try fingering/oral before penetration?
Some guys just keep going for a second orgasm after they've first *** but this doesn't seem to be the case with your boyfriend. I've seen advertised 'desensitising' creams that claim to help a guys 'staying power'. Maybe that's worth looking into?
It depends. I can sometimes continue after one ejaculation, but never if it's condomless sex and I come inside them: the semen means it gets very slippy in there! If I come outside, it is often possible.