excessive mastubertaion

i am 23 yrs male.i matubarate every day and even somtimes twice a day. i have been dng this since last 8-10 yrs.i want to know whether this is normal.Will this effect me while dng sex.Couple of months back i had a plan of dng sex with my girlfrnd but my penis didnt got any erection.does erection has any relation with mastubertaion.plz help me as i m really very scared.Can u also tell me the normal length of penis.

Masturbation is perfectly safe, normal and healthy.
Masturbating a lot will not damage your health in any way.

Chances are you couldn't get an erection because you ejaculated at some point close to when you had sex.

Basically, if you come say 3 times in one day, if you try to have sex later that day, you might not be able to get an erection.
But there's nothing wrong. It's just like going jogging and then being tired afterwards.

So if you think you're going to be having sex in the next few hours, don't ejaculate. You *can* masturbate, just don't come.