PSA seems low enough to warrant that the drugs are working, but since you have no baseline to compare to, I'd leave it as doubtful still.
If I had to bet, I'd say they are working though, 0.4 ng/ml seems pretty low. But then again, you're only 22.
Your total T seems high enough to suggest they are working as well. And the fact that you're a NW4 at age 22 with little or no further progression of hair loss for over a year and a half.
You just have unrealistic expectations of what finasteride/dutasteride actually do, they rarely regrow hair back a norwood stage, let alone two.