StormRider or any other guy that has this problem... Don't sweat it. There are things you can do. The first step is admitting to the problem. The next step is working with your GF/wife in a loving way to correct it. They know what they like/want/enjoy, so get them to tell you and instruct you. Look up resources on the 'net. There is some great info out there on this subject.
If you have a problem with your "equipment" (ie erectile dysfunction or premature ejaculation), talk to your doctor. There are drugs to help "get it up", and you can practice and buy products to improve your staying power.
You don't have to accept being lousy in bed. It is like lifting weights... if you want to be stronger, do something about it.
R