I’ve known since I was 14 I was trans, ended up just having to suffer till I was 20,
Lots of folks go nearly their entire lives without figuring it out. Some even go to their graves still not figuring it out after a lifetime of misdirected malice.
You knew at 14. You made changes by age 20. By this metric alone you are already far ahead of many that have gone before you.
I realize my body is just gross and repulsive regardless, like my genetics are just cursed.
This is most of us. When I say "us" I mean humanity. An infinitesimally small number of us are physically perfect. These are the ones that end up on magazine covers and in big budget Hollywood movies, and many of those suffer devastating mental struggles we don't see on the outside. Even most of the "beautiful people" have people have physical flaws. They have developed skills to accentuate their better attributes or cover up their less socially acceptable ones. These are NOT our archetypes to measure ourselves against. These are this era's definition of physical beauty, thats all. Look at history for previous eras and see what used to define the pinnacle of beauty. Most would seem plain or even undesirable by today's standards. So why is today's era definition any more logic driven? Its not. Don't compare yourself to it.
I think at 23 ... and pull the trigger.
No. At 23 you're not yet the "you" you will be in life. Our 20s, in western society, is when we learn about who our adult selves are. You're not even at the halfway mark yet. Don't let the 23 year old version of you decide to deny the existence of your 29 year old version, or you 80 year old version.
I just feel so horrible but I’ve been in pain so long I honestly feel
You know all of those stories and movies that let the protagonist return to their teens or 20s to repeat things or do them differently? The fantasy is having your mature adult brain in a youthful strong body. Its never to return to the angsty mental period of our teen years or the difficult struggles for identity of our 20s. In your teens and early 20s everything is emotionally extreme. There are the meteoric highs of happiness, and the devastating troughs of sadness and despair, and very little in-between. Getting older into your late 20s or 30s changes that. The sharp emotional edges are softened a bit, the extremes at either end are kept in check, and there's SO MUCH MORE MIDDLE AREA and its so much better to live with! Yes there are still things that suck, and life will have some really hard times ahead of you, but you'll be able to handle them easier. You'll also have ahead of you much longer periods of happiness that can stretch years or decades. Not like the feeling of "winning the lottery" happy, that is always fleeting, and rarely realistic. Instead you get "comfort". Like holding a hot mug of a beverage on a chilly day, and you get that warm contentment for years at a time!
Asking the questions of yourself is fine. Its good even! Seek the wisdom of those that have gone before you, and asked some of your same questions. Be open to answers you hadn't considered before. For your situation specifically, find groups of others that have transitioned already. Don't let others define an unrealistic measure for you and then call you a failure for not meeting it. Don't do that to yourself either. Don't deny your future self the life you have ahead. Find someone you trust to talk to about your feelings. I promise you, life is worth living.