Should I feel tingling when jelqing ?

Hello,

I am complete beginner and only jelqed 3 times (JPs 90 routine), and have some questions:

- I have trouble maintaining erection for more than 10 consecutive jelqs, so I have to stop every 7-10 jelqs and jerk off to get my penis hard again.
Is it any good jelqing like that or do they have to be consecutive (no blood released, because your hands are always gripping the penis) to be effective?

- When I did jelq for about 15 times with a bit more pressure, I felt slight tingling in my head. Does this mean I am overtraining or is that the sign that blood is there and my penis is being worked correctly ? When I didn’t get to 10 jelqs I felt nothing.

Thanks in advance.