Hey man, sorry to hear about all your troubles. I have read that finasteride really fucks people up for a long time. should be a warning label on that shit.
As far as options go, give Eric's article "Fighting Gyno" or somesuch a read. It's on the forum here. It will tell you how to boost your DHT. Basically you can rub testosterone gel onto scrotum, use Andactrim gel, or shoot Masteron/take proviron (high dose creatine might work as well). Proviron and Masteron aren't fully real DHT so i don't know if they would help you. if my thinking on your idea is correct, you want to boost 5AR enzymes. So I would think that a test cream applied to a scrotum would be best, as everything else is already 5-alpha reduced and the test would supply substrate for conversion by 5AR enzyme. I am currently running masteron for gyno purposes and it seems to be working, very nice libido boost. It is definitely stronger than AndroHard V3 was, in terms of libido, and I think it is stronger in terms of gyno reduction, but it hasn't been long enough to tell.
Where are you located? Why not try going into a TRT clinic and trying to get a script for some AndroGel? some of the ones that advertise online are really really cheap