weak erection with ejacuation

Hi i m 20 ys old and experiencing too weak erection from about 3 months now.somtimes the erection are completely normal but sometimes its hardest job in the work.i am too much exhausted and worried about this,

This started a few months back when i was about get physical with my girlfriend and i over ejacuted and deprived myself from getting an erection ,initially it was like i thought that i must have snapped my nerves but sometime later i was curious about it and was becoming emotionally unstable,I had no erection at all but I was ejacuating without masturbation and when I consulted my doctor he examined and told m they were normal ,I still get some erection but they are not consistent. I am really worried about this I get erection but not always and sometimes after masturbation I don't get any erection for few days and after some days I get erection but weak erection they are never as strong as they were after that imcident with my girlfriend...kindly help...any help would be appreciated ..sorry about my English I don't know where to start and where put my words....plzz help

You are probably overmasturbating.  It can damage the inside structure of the penis.  Masturbate at most once every 4 days.

I am not sure but i don't understand about the ejacuation.They are happening without any reason without any arousal 

sachin, it's simple: the less you masturbate, the better the sex with your girl! biggrin