How do you control it?

Be older
 
Imagine that you are fucking an 80-year old woman. When you start to lose your erection, focus back on the woman in front of you.
 
kegels, reverse kegels, careful pacing, practice.

Can't say I've spent nearly as much time as I should have on that last point, but developing and having better control over those muscles will go a long way.
 
Advise and tips on how to not cum too fast during your session
Jack off at home before going to your appointment.

When you are getting close, squeeze (or ask her to squeeze) the glans while pulling down on your scrotum. This will buy you a couple of extra minutes.

Why is cumming too fast a problem if you are seeing a sex worker anyway? Just go for MSOG.
 
Change positions. Within each position, vary the depth, speed and angle. The more variety of sensations, the better.

B88
 
Do intense cardio for about 30 mins for 3 days a week. You want your heart rate at that athletic training zone around hard and maximum. Also have more sex.
 
I've always had problems cumming with GFs and my SO. SPs have helped me as I can hit the 30 minute mark with focus (like I'm in porn). Some SPs really have the stroke/push back down pat. I still can't make it happen with my SO.

To the OP: Perhaps jerk off a few times before seeing her?
 
Do you masturbate a lot? I do, at least once a day, sometimes twice or even three times. It helps me in two ways. One, it helps me learn my body to the point where I can tell when I'm in the home stretch and as far as 10 minutes away from finishing. So I can either then slow down or speed up depending on what I want.

Also, the repeated action dulls the sensations on your penis slightly.
 
Practice edging when you're by yourself. It's a good way to train your body to know what your point of no return is. When you feel you're going to pop, slow the pace down. Know your limit and stay within it, so to speak.

If that alone doesn't work, pull out and enjoy some DATY for a bit then go back to it. Repeat if necessary. Speaking of, I've never been with a woman who didn't go crazy from my sex/DATY/sex/DATY/sex routine. You can also try thicker condoms. Practice makes perfect. Good luck. ;)
 
Precisely. Fix the problem by delaying self gratification when you're jerking off. Learn to slow or stop yourself. One thing that works for me is to force my dick downward as if pointing to the floor. It's slightly uncomfortable when you're rock hard, so it buys me some time.
Another tip is to distract yourself with something detailed. For example, if you're a Leafs fan, in your head name every player, position, etc...... Just don't become so focussed that you lose your hard-on because you can't remember Ron Hainsey's jersey number.

Awesome! lol
 
Try a cock ring