i don't know if it works the same way for guys, but generally the quicker i cum, the less intense it is. you could try to build up and get close to orgasm, then stop or slow for a little bit, then work back up and back off a couple times before you let yourself cum and see if that makes a difference. i'd think the more intense your orgasm was, the more force you'd ejaculate with, but like i said...i'm not a guy, so i'm not sure it's the same.

afraid i can't be much help on your other "problem". i think you're a perfect size