there are some therapists out there who sometimes include treatment of this as one of their specialties…maybe you could do a Google search for your area.

fwiw i've always thought this problem was related to generalized anxiety; also it depends on the woman (if she's critical or hostile or impatient it can make it much worse)

also it's now called "rapid ejaculation", to eliminate the judgment inherent in calling it "premature"

one other thing something interesting i read one time--to what extent is it a problem because it's not when you want to ejaculate? that is, do you *really* not want to and do it anyway, or perhaps are you interested in getting off as quickly as possible?