It hurts

In the end I developed RSI. I only do 2 thing in my life

  - Fapping
  - Programming

I truly wish it was caused by the second.

Now seriously it seems that my touch typing isn't the problem, it has to do more
with the mouse usage. Any technique or product I could use?

As a background during my teens I used to do a lot of BMX, so i was always
working my wrists, but in the last year i stopped that. could it be that a
cause?

Do daily push ups and pull ups when you get strong enough, that is assuming your body is not too damaged to achieve the exercise. What I did was to start doing sets of 10 push ups on the hour every hour. I started increasing the sets by small increments as the days pass on: 12, 15, 20, 25. Eventually over a number of months of daily exercise, I found I was doing sets of 150 three times a day and that my lower level RSI had felt much better.