Most men only wish they had your problem!:cool:
Another position that you can try is to sit upright together, legs wrapped around each other, with her on top.
You can also try masturbating until you orgasm and then having sex. It's normally not as hard the second or third time around...
Google "sex positions" or like we said in a previous post, there are tons of good books at amazon with different sex positions. There are hundred of positions - surely you can find more than just the missionary position that works for the two of you.
Again, this is about working with what you have and finding what works for you. The good news is that as you get older, your erections will very likely get softer...
Also, talk to your doctor about this issue. I'm sure he or she will have some great recommendations and possibly even a magic pill to help with your issue.
We don't recommend taking medication unless it's absolutely necessary, but it's worth talking to your doctor about...