How do I start?

Hey, so im considering going DIY! After sitting through all the NHS psychological reviews and whatnot I dont want to sit on a 3 year waiting list.

I could use some support and some answers if you guys could give me a hand.

Where do I begin? Do I get bloodwork done first? Do I need to figure out a correct dossage? If I do how? Anything else really important I need to know?