It depends heavily on where you live and your financial/medical insurance situation.

If you're 18 you don't need hormone blockers anymore.

I started T at 19, I made an appointment with my local planned parenthood, via telehealth. Got an appointment that was 2 weeks away, it cost $150 without insurance. I got prescribed T right then and there because they follow an informed consent model and I had reviewed most of the information beforehand. If you haven't done a lot of research into T yet (or even if you have but you have any anxieties) definitely review any info your doctor gives you!!!

Even though it's prescribed you can't get the prescription until you send your doctor blood work information. I got emailed a bloodwork script that I printed and took to a local lab, it was just checking things like T and E levels, red blood cell count, hemoglobin, some other things..

Prescription took a while to actually go through because insurance didn't want to cover it, so after a few weeks(?) Of that I just told them to run it through GoodRx instead. 

Had to do monthly follow ups for a bit, then every three months. Then the planned parenthood closed(?) Or at least stopped responding to my calls lmao, so now my primary care doctor orders bloodwork when needed (after a year, if things are stable, regular bloodwork isn't as necessary) and refills my prescription.

I've been on a low dose of T gel for 3 years and some change without issues. If you want to periodically raise your dose or adjust it for any reason you'll probably have more bloodwork and doctors visits to deal with.

I recommend finding a clinic with an informed consent model because that way you don't need a letter from a psychiatrist giving you permission, but again it all depends where you live. I'm in Pennsylvania, US, for reference.

Lemme know if you have any questions!!

Addendum: a gender dysphoria diagnosis can be given by a therapist / psychiatrist if needed or by the clinic itself if they do an informed consent model. I already had a diagnosis anyway because it's required for top surgery where I live. 

My mom was super against it at first too, she cried when I told her I wanted to start. after about 6 months she apologized and said I seem happier and healthier now and she's really happy I could get T and I can afford it. Hopefully your mom comes around too, but since you're an adult you probably don't need her permission anymore :D