Sounds very similar to me. At 17 I was a Norwood 1.5-2. At 19 I was a 2.5-3.0. At 21 I was a solid three. I think the follicare system bought me some time, because from 19-21 when I was using I saw some thickening. But at about 22 it really started going, bascially right when I stopped using follicare. I got a hair transplant by a scumbag doctor(dr.thomas wentland) and it was the worst mistake ever. At 24 I was a solid Norwood 4. Now at 26 Im a diffuse Norwood 6, meaning the pattern is still a NW4, but the hair is just so thin Im basically bald NW6. Now I just buzz with a no guard using a beard/mustache trimmer(they get much closer than a no guard on a normal hair trimmer) and just continue my day, scars and all.
At 22 I used propecia and rogain foam and folligen for a solid two years. I lost more hair in those 2 years then anytime before. About three months after stopping the follicare system I saw my first major shed(about 21.5 years old). I should have never stopped it. Although I wouldn't use it now becuase they put a herb in their new formulation that I am concerned with taking. Then I used propecia and rogaine foam. Literrally, a few days into using rogaine foam, I saw another huge shed. It was all down hill from there.
Now, I am doing the immortalhair regiem as a last ditch effort. Slowly working my way into it. I will give it a solid year, but I am not expecting much.
Good luck.