Need advice/Insight with hairloss please

My hair has slowly been getting thinner since i was 16 and now at 18 i shaved my head for fun but when growing it back the top looks so thin.

I saw a dermatologist and he said my hair isnt falling out which tbf it isnt, i dont really see any on my pillows and barely in the shower, but i swear to god its gotten thinner pretty much all around my scalp and i fear im close to getting a bald spot (although there is no bald spots on my shaved head?) its just when ive grown my hair to buzz length the individual roots look smaller and i can see my scalp under light.

The dermatologist has given me minoxidil and has told me just be more healthy which i haven’t really done tbf but ive take minoxidil pretty consistently for about two months now and i don’t notice a difference, and he also did no lab works so im going to get my blood taken for things like iron, thyroids and vitamins and rule out anything.

If everything seems fine with blood, i think the ultimate next step is to take finasteride and im wondering if thats okay for someone who is 19? and if its something that will actually since i dont notice alot shedding? Another thing it could be is stressed since i was stressed all through highschool to the point i went to a therapist and im still not " happy " but its livable and i feel like hair loss from stress would be back by now since its been half a year.

Sorry if this long but i really wanna change my life around and my hair makes me super depressed so i want to know if i can hop on fin plus minox oral and just not worry about it while also being 100 times more healthy?

Hair loss can be caused by many factors, so blood work is a good idea. A dermatologist should be able to differentiate between androgenic alopecia and other hair conditions. Minoxidil will takes more than 2 months to show significant improvement. Finasteride stops up to 70% of DHT production in the body and in the context of hair loss, it’s only useful for androgenic alopecia.
You are 19 and not shedding hair, suppressing your DHT is not healthy, so take a step back, discuss your concerns with your dermatologist, if he doesn’t listen to you, go to another one. If you are diagnosed with androgenic alopecia, then taking finasteride would be the way to go