What is the possiblility of premature ejaculation?

Dear Ask The Doctor: I have a new girlfriend and I am concerned that sex doesn't last as long as it has done with other partners. After researching premature ejaculation I am convinced that this isn't the case here. I cant seem to stop myself ejaculating when i want to and this is having a serious effect on my self confidance! I would love to know why this is happening and if there anything i can do to sort it out? PLEASE HELP!!

Dear Dean: You are most probably suffering from performance anxiety which is causing your symptoms. I would suggest you to talk with your partner regarding your anxiety, fears and apprehension.