You have obvious androgenetic alopecia. Mine started at 16. I hate to break it to you, but Finasteride and Dutasteride won't help you, although the "experts" on this forum will assure you that Finasteride will work if you give it enough time, like 6-12 months. But in practice, these drugs don't work on people who started going bald at an early age. So your prognosis is complete baldness within the next few years.
Treatments that can stop and reverse early baldness have side effects that not everyone can live with. Personally, I went on HRT, and to you that may sound radical, stupid, and dangerous (I thought the same when I was 18 and taking Finasteride).
So I'm not giving you any advice. But I have warned you about the prognosis so that you don't waste your time on false hopes. What you do next is up to you.