He can't get it up...

What should I do, we've tried lots of things but he just can't get it up that often and when he does, he can only ejaculate if he gives himself a hand job. So while trying to conceive, I get on top when he has eject later or right before he does. He can't even do it while on top of me and doesn't get how to thrust up and down. Maybe because he is out of shape and has a belly. Just really need help. The more he realizes he is bad at this, the harder it gets for him to even ejaculate the way he knows how. 
Any suggestions?