No Erection and Smaller Dick

Hey guys

I got some questions and I thought this could be a good place to ask them. I've been doing nofap since april kinda on and off. I always can do it for 1-2 weeks but then ill loose my "challenge"
Ill have to say that I wasnt really too addicted but I was having minimum 1 wank daily and watching porn by it. But then I started some troubling thoughts;
What if I meet a girl one day and cant get it hard because of my habit? I aint a virgin but I also dont have had very much sexual experience, but when I meet somebody I wanna be ready for it, I dont wanna be no disappointment.

Also I saw that nofap should have a lot of positive things like higher testosterone, the dopamine in the brain gets kinda more regulated and I also heard of a confidence boost like experience. Ok sorry for the long talk but Ill get to the point.

Im now at it again on day 20 of nofap But since I started it I havent got a full errection. Not even 1 time. Sometimes ill get around 80% but thats it. Before I would have a full erection every once and then but meanwhile I never got it again since I stopped masturbating regularly. I once put porn on to watch if it was because of that but not even then it got Hard like it used to. Besides that it kinda looks smaller. Not because I aint got a full errection, even the 80% look smaller. Its kinda worrying me, im even thinking of visiting a doctor.
I mean im 21, thinks should still work fine down there but they dont. I mean I already was insecure aboutmy size before that problem, but now that im down at 13-14cm im kinda even worried not to be enough if I find myself a girl that likes me.

Well sorry for the long ass text i've written you but I hope someone of you can help me / tell me what it could be.

Thanks for your time and have a great night