I believe that often a lot of it can be in your head (the one that sits on your neck, lol). You may be psyching yourself out - like, the more you are afraid of it happening the more likely it is to happen....
I have read\heard that masterbation(sp) can help, because it helps train the person to take their time. I would also think that EFT or the techniques used in tapping the healer within might help.
Your best and proven solution is to do Kegel exercise go to www.kegelexercisesformen.com
for instructions in how is done. Best of luck and good health to you.