HRT is a double edged sword. Yes, it can help a lot with the GD, the depression, and quieting the noise in your head. But it can and usually does have an influence on secondary sex characteristics, aka breasts, among other physical factors. Finally, there is my wife's sage warning of "Estrogen will mess with your head".
For decades I relied on my on/off Brain Reset of low dose HRT, usually just estrogen. After about a month or so my brain was well reset followed by evidence that "The Prime Directive" was being violated as things were starting to take a hit below the belt

That didn't jive well with being a "Normal(ish)" guy and my SO at the time was soon to notice that.
I tried all sorts of tricks over decades to keep the GD under control. Mostly what I call the 3D's; Diversions, Distractions and Denial. I eventually came to a point in life I needed to take the Trans-Best on for real. The only regret I have is the pain I am causing my wife. I wanted to be a girl ever since I was little. But at 6ft tall, big everything, deeper then average voice and balding since 14 that wasn't going to happen. Two utter failure transition experiments proved it wouldn't be. I settled on being "Just a CD"... with a dream.
Knowing you are trans is simple. Where on the spectrum is a far more difficult question to answer. Plus the answer is bound to change as you move through life. It could go from more towards female, or even back towards male.
HRT is a Major medical step towards transition. I believe in the UK you are required 1 year of RLE even before you can get them. The theory, I guess, is so you can experience, for real, life as a woman before taking any, possible, irreversible steps.
Plus, as you see there is a lot of Reality Therapy need. A ton of factors we tend to gloss over or ignore in the quest for peace. An experienced gender therapist can help interject some reality into the dream or fantasy of actually living and being a female.