21 years old have always had a very small penis but 2in abnormally huge erections 9in my growth stopped around 17 yrs old and now I have noticed a girth increase when I was 20. Normal in both regard?

That's fine. That's a normal flaccid length and an erect length that will make most men jealous and be incompatible with some women. Stop worrying. There will be somebody for you. Learn to use not just this special asset, but your entire body, to be a good lover. Communication is the key. Best wishes.