First Question:
i have a Pre-Mature Ejaculation problem. i reach my climax and ejaculate in less than 45 seconds. the thing that you should know too that i can have sex like 3 to 4 times averagely in one session with my wife with no erection troubles but in the 2nd and 3rd sessions my ability to control ejaculation lasts longer than the first one and it might reach 1min:30 seconds to 2 M:30 S.

My question is: is many ejaculations per session an abnormal situation? will this way of sex life hurt me or have a negative consequences on me later when i get older, i am 26 years old now,? does this effect my sperm count or make me more vulnerable to Prostate problems?

Second Question:
As i mentioned already that i have a Pre-Mature Ejaculation Problem, and i read about this technique called Stop-Start technique that helps improve overcoming this problem. i read the following:
Set aside three 20 minute slots each week, when you can be private and uninterrupted.
First masturbate very slowly, noticing carefully what sensations you get in your penis at the increasing levels of arousal before you are ready to come.
At the point just before you would come, stop touching and wait for the intense arousal to go down. You may lose the erection, but you will get it back. If you were too late stopping, and came, try again later, and stop a little earlier in the arousal.
Repeat three times, then allow yourself to come.
Do this three times a week, and after three weeks you should notice some improvement. Carry on, and you will overcome your problem.
My Question is on item number 3: For how long should i stop? can you put it in minutes or seconds to help me do it more accurately? do u advise this technique? does it have any negative effect later?