I am 18 years old, 19 in 2 months or so, I have been experiencing erection difficulties for the past 3.5 years. I can remember clearly the first time this problem happened and ever since this i have strongly believed the reason is that i am simply frightened that it will happen again and cause me a lot of embarrassment.
I have tried kamagra to assist me gaining an errection however the idea that i will have to take this and have to plan to have sex for the rest of my life has caused me great depression. I have smoked cigarettes and cannabis heavily (daily) for the past 4 years but for the recent 8 months have realized this may be contributing to my problem and have slowly cut down and finally completely cut the habit along with not drinking alcohol at all.
I did little or no exercise for the past 4 years but have increased this alot to atleast 20 mins of fast paced running every other day which i can tell myself is improving my fitness levels. My diet was also very unhealthy in which i have improved greatly, i eat alot of fruit, i take codliver oil tablets twice a day, vitamin C supplements, alot of vegetables, i drink alot of water and basically i know i have improved my overall health as much as i can.
I first started masturbating at 11 years of age and have been constantly doing so 2-3 times a day, each of these sessions consisting of several orgasms, i am able to hold in my sperm whilst experiencing an orgasm and within about 20 seconds i am ready to carry on, almost as if one orgasm doesn’t satisfy, so sometimes i may have 15+ orgasms a day. I seem to always think about sex, constantly thinking about it whenever i see any attractive woman however it seems that i cannot control my sexual urges. I have a girlfriend and i have successful intercourse with her quite frequently. However, whenever she tries to have sex with me, i am not sexually stimulated at all, in my head i am thinking yes definitely want to do that now, but my body completely just denies me of feeling that way. It’s almost as if i randomly become horny and just use my penis when i can, i cant seem to gain an erection when i want to.
I have just started to stop masturbating and im going to try to just have sex with my girlfriend once a week with no masturbation at all. I am very tired all of the time with alot of concentration problems, i have an occasional pop and ring in my ear for a few seconds this happens approximately 3 times a week. I have alot of memory problems, i now have from what i have been told by my doctor as anxiety attacks quite frequently with my breathing patterns. I know that these things such as memory loss, headaches and being tired/lethargic all the time could also have been caused by the smoking of cannabis i do take this into consideration. I also experience blurred vision quite frequently and am currently under alot of stress due to my A-Level studying and thought maybe this may be a factor aswell.
Another thing is that i seem to be more sexually stimulated when i am about to have unprotected sex than the thought of putting a condom on, when i do this i am usually limp by the time i have put it on and then im useless. 
/Mousz555/
This is overdoing it BIG TIME. The uncontrollable sex drive you have may be a mild sexual exhaustion PSAS. It matches will all the other symptoms you listed.
Diminish masturbation immediately and supply your organism with vital building block amino acids and vitamins as soon as possible.
I agree with Markus. You’re almost certainly suffering from the mild stage of sexual exhaustion – ref. https://vimeo.com/113147667
You have 2 to 3 years to continue these practices before you reach the serious symptoms of the moderate stage. Better stop now because going back from the severe exhaustion is both costly and difficult.