I've combatted hairloss and won. Luckily, I only needed fina and it was a life saver. A miracle drug.
Hindsight is 20/20 but I'd say don't use dut until you are sure fina won't work. I've heard of gyno on dut, though it is fairly rare. It happens because in some guys, the extra test that is not converting to DHT aromatizes into estrogen, and you get gyno.
dut blocks 90+% of test to DHT conversion, and fina about 66%. Anti-es will help IF you catch it early enough, but if you are already showing gyno, surgery is the only sure cure.
Dut is powerful stuff. Sucks that it gave you gyno.