I know that this can be so frustrating and disappointing to deal with at times.
I have 2 boys with LOCAH and we are constantly trying to figure out how to preserve their height as much as possible. Looking back at their labs over the last few years and knowing what I know now, I realize that they were both oversurpressed for a couple of years and didn't grow much at all. My 13 year old is 5ft. 1in. (I'm 5ft. 3 and my husband is 5ft 9) and last time (6 months ago) we checked his bone age was at about 14 and a half. He is taking letrozole to try and keep his bones from fusing but we don't know if it's working yet. He's barley grown at all in the last 4 months and his testosterone levels have been over 2000, so that's a little scary!
On a positive note to you, I have definately heard that some men still grow into their early 2o's so maybe the doctors don't always know for sure what they're talking about.
Good luck to you!