My crown is thinning, so I'm looking into the cost of hair loss treatment.

Lately, my heart sinks every time I see a handful of hair falling out while shampooing... It breaks my heart. Even changing my parting doesn't help; I can still see how thin the crown of my head is, so I'm debating whether I should buy hair fibers. I don't think just applying scalp essence and taking supplements will be enough, so I'm looking into hair loss treatments that have good reviews in online communities. I heard the effects are immediate because they inject nutrients directly into the scalp, but since it seems like this will be a long-term battle, the cost is my biggest concern. They say you usually have to go once a week for several months to see baby hairs growing in. Roughly how much should I expect to pay for a one-month treatment? Please, those of you who have successfully grown thicker hair, share some tips!