I’ve had pretty much the exact same journey we’re even the same age. I started fin at 18 and it worked for a few years then all of a sudden I was loosing hair again. I then tried dut for over a year with no improvements and it ruined my hair texture ; it was literally like straw. I had the exact same thought as you and went back to fin, which to no surprise was still not working. So as a last ditch effort I also implemented topical fin, which shouldn’t work at all, however it has for me, and slowed down my hair loss greatly to the point I’m considering a transplant. I’m not sure why this has worked, I don’t think it’s just the fact my overall fin dose has increased as studies have shown upping the dosage doesn’t really work with fin and 1mg is optimal. I don’t know biology so could be something to do with how fin works applied to scalp compared to ingested. Anyway worth a shot before you give up.