Use Chinese Brush. Go in a sex shop, ask for it. About one hour before sex, apply LIGHTLY (don't overdo it cuz you won't be able to cum) all around your penis where the head meets the body (under the head). You can take a shower before sex if you want. Believe me, this is way better than those shitty creams.
I used to have the same problem, but with Effexor (antidepressant), it's not a problem anymore! I can only get about 85% hard though and my erections don't come as spontaneously as before. That's why I ordered Cialis! Can't wait to get it man!
Oh, and if you cum in 30 seconds, can you do it a second time with a minimum break? If so, you don't have a problem, unless you are like that kid in American Pie.
Andre