Hi redki,
This is a lot longer than I thought it would be, feel free to skip down to the "Long story short" bolded words.
Like you it wasn't until my adult years where I began questioning my gender identity. I grew up as a tomboy and proudly embraced the rough and tumble lifestyle of sporty kid who enjoyed playing with the boys. I wore "boys" clothes from the time I was able to begin choosing my own right through to this day. I had to bribed just so I wore a dress, but even then I'd be wearing some "real" clothes on underneath. All the while I never once questioned if I wasn't a girl as I had been so swiftly assigned at birth no thanks in part to my genitalia.
The term transgender wasn't ever on my radar until last year, alongside the term nonbinary. I didn't know there were genders other than boy/girl or man/woman, I felt like I had been living under a rock my entire life. I suppose that I have.
I kept this revelation a secret for months, worrying over it like an itchy scab. I have clinical depression, and this set me off into a spiraling abyss. I was at breaking point when I finally had enough. I fought with my mother on an almost daily basis, I was irritable and highly strung. I had hidden this monster in the closet to the point where it was fighting for a breath of fresh air, clawing at the walls of my sanity. It was around one in the morning, late in March when I finally stopped trying to hide it. I had gone outside and was just standing there, watching the night sky. I didn't have any intention of coming out, I don't even know why I went out there. It was a clear night, and just as my mother began asking me what was wrong, a shooting star flew across the sky. The floodgates slammed open, I couldn't keep this a secret any longer. I told her whilst fighting tears, standing in the yard while she stood under the patio as I didn't want to be close enough to see her expression.
To my absolute relief, my mother was accepting, as was her boyfriend, a man I consider my father. She told me that she knew I was different, that I had been like this since I was a kid. She told me that I could do anything I wanted in life, provided I did so with an informed state of mind. It was a relief to not have to hide anymore, I haven't had an argument with my mother since.
The day after I booked an appointment with a gender therapist. Prior to this I was considering moving out, was considering to just skip out for the day and somehow make my way three hours north to get this appointment. I don't have a licence and don't have a car, so it's not much of a stretch to imagine how worried my family would have been if I simply wasn't there one day.
I made the appointment in late March and the earliest was for Mid June. I went to that appointment last week, and it wasn't what I expected or hoped for, but it was a start. I now know the steps I need to take, the direction I want to go. I'm not certain if I am FTM or not, but I do know enough to comfortably say that I do identify as transmasculine. I plan to go to a not-so-local support group next month, which I hope will give me some "real life" experience with other people like me. I'm an introvert and socially isolated at best, so going there will be an exercise very much out of my comfort zone, but I want answers, and I want to be comfortable with what the future might hold for me.
The monster wasn't really a monster, it was just a part of me that was so starved of acknowledgement that it resorted to extreme measures to be noticed. I'm still trying to embrace that I'm transgender, and I'm still coming to terms with the knowledge that I've been so disconnected with my feelings and emotions that I didn't notice this earlier. It's the thought of turning my unhappy existence into a possibly fulfilling life that keeps me going, there's a chance for me and I don't want to let it fly me by.
Long story short, it's not an uncommon narrative where someone questions their gender identity later in life. It might not be the stereotypical story, but it's one that you and I, as well as many others, have experienced. I certainly didn't know earlier, although at times I did feel like things weren't adding up. I'm glad I found out though, even if I do feel like I've been living under a rock. At least now I have a somewhat more optimistic approach to what my future might hold for me.
I'm going to suggest to see a gender therapist as well, the sooner you make an appointment, the less time you need to wait sorting through these feelings by yourself. I'm a stubborn son of a gun when it comes to dealing with problems by myself, and it took me eight years just to get help for my depression. Eight miserable, this isn't living, it's existing, years. I hated being in that predicament, and I dislike the idea of someone else going through it too. At least with gender therapy it only took me six months to seek help, and another three to begin receiving it.
If you think you're ready for gender therapy, I think it would be a good idea to make that appointment and see how it goes. My therapist helped me realise that even if I don't really know where on the masculine part of spectrum I am, that I do need to seek further transition. Social isn't enough for me, I want... no, need medical transition to feel comfortable in my skin.
I'm going to parrot Jenna Marie and also suggest to experiment with expression or other social transition steps. I already had the masculine expression down pat before questioning my gender identity, so my steps began with coming out, binding, name change and pronoun change. The latter two are a work in progress, but again, it's moreso to do with my doormat personality and extreme dislike for inconveniencing people than anything else.
Best of luck in your journey redki, I hope my post wasn't overwhelming.