Well the back pain and memory loss maybe a psychological problem and you are just imagining it or in other case is not connected with masturbation.
The next point is masturbation for 3 or more times a day well, normally masturbation is not bad except in cases when you are obsessed with it.
Maybe you need to visit a psychologist to talk about your insecurities and try to find a GF to supplement the number of masturbations a day with normal sex.
Masturbating to Inteernet porn can eventually cause erectile dysfunction. If not with porn then the ED shows up with real women.
We have seen it again and again on our porn recovery forums.
Just a note, excessive masturbation to porn keeps many young men away from the real-life relationships. Can your relate?
Here are two excellent presentations, by a science teacher, on the effects of pornography on the brain. They are non-religious, non-judgmental, and science based.
Erectile Dysfunction and Porn:
Your Brain on Porn - Porn Addiction:
Getting away from porn and replacing it with human interaction is your best cure
I would suggest maybe it;s time to start looking for your perfect person more actively, as a previouse person said, getting away from porn and replacing it with people is by far the best treatment that could be offered to you