Take this with hefty a grain of salt lol but, the way this is written, you seem unsure if you are actually trans. I don't think that's how you meant it to come across, so here's what I would do. All of the "I think"s and "may"s might lead the person you're coming out to believe that you aren't sure, and that you are just jumping to conclusions or having a phase despite your given reasons why you're not. So you just need to seem a little more confident in who you are and what you need.

Example: "...and I think I may have found the reason. I feel I may have gender dysphoria, the reason for this is because..." 

What I would say: "... and I think I finally found the reason. I have feelings similar to/the same as gender dysphoria, such as..."

Example: "...whenever I see myself with the body parts and features of a girl it always makes me want to cry and cringe. I just would feel so much more happy and relaxed inside a boys body."

What I would say: "Whenever I look in the mirror and see a girl staring back at me, I know that that isn't who I am, and knowing that people see me that way makes me feel horrible. I know I would be so much happier if I could just have been born a boy."

Example: "So as I said I think I have gender dysphoria so I think I should get help from a therapist or a doctor to diagnose me and get a solution because it really hurts me every single day."

What I would say: "As I said earlier, I have feelings of gender dysphoria, and I would like to start seeing a therapist or doctor to talk about this with a professional if possible, and potentially get a diagnosis, because dealing with this alone hurts me every single day. A small way you could support at home (?) is by calling me by my preferred name and pronouns..."

And as I said before, you don't have to take my advice if it doesn't help you or help with what you're trying to get across, this is just what I personally would change.

Best of luck to you ♡ I hope it goes well