Hair Loss - Accident Recovery Related?

Recently I have noticed my hair becoming extremely thin (always very thick) and been experiencing rapid, excessive amounts of hair loss with no regrowth.. All within the span of about 4 months. I'm 24, not too stressed, casual smoker/drinker, and have had my thyroid and other hormones checked and they're fine. I am going on my third year using Oxycontin as well as other opiates on and off after a severe motorcycle accident... I have had many bone and nerve surgeries subsequently.I haven't been very active since the accident and for a short period my diet wasn't up to par, but is now.   I haven't read anyone else with a condition quite as similar- without any hair growth. If the use of Oxycontin is stopped (if thats what it is) does hair grow back? I have noticed my muscle mass declining rapidly as well, figuring that is probably related. Please, any ideas?