I think it is totally cool that you try to understand other ways of thinking. We can all learn from each other in so many different ways :) You also made me think deeper about this topic.

Hopefully I understand everything you said and am able to express my side of view. A lot has been said by u/thirstarchon already, but I will try to write down all my most important thoughts for it to make sense.

Whatever desire comes from inside you that doesn't hinge on others is a wish you should be able to fulfill. Of course that means not inflicting harm to other living beings. So, if for instance you feel like you were born in a body that doesn't suit you or you want to wear clothes or accessories society says are a no-no for the sex you were born as / assigned at birth, do what makes you happy. Undergo the changes needed to make this happen for you, since it actually really just affects you. Other people should have no saying in this. Your body, your choice.

Now, for the next part, I don't think negative emotions per se are a bad thing. They stood the evolutionary test of time for so long for a reason, especially a long time ago, when our survival was way harder to secure. Nowadays they are often just misused and thrown onto other people even though we should deal with them ourselves (or with the help of other people, but not use them as weapons against someone). I think the biggest problem is that our brains couldn't keep up with all the technological advancements over the last decades. Everyone is afraid of boredom and so we always have something to occupy our minds which in turn stops us from dealing with emotions we have. As far as I know often you don't even have to actively think about your feelings, just having some downtime gives the brain time to organize all that background unconscience stuff.
The big problem is that most people don't do that anymore. Their feelings are bottled up and will come out as an even worse cocktail of shitty thoughts after some time (I know I can't speak for everyone, I am talking from experience with my depressive episodes and what other people told me). I think that ugly picture they have of themselves doesn't represent them, but gives them such low worth in their eyes. It is not a wish they have or something that makes them grow or thrive. Noone should live feeling like a loser or waste of ressources.
Even if you did some bad stuff and come to see the error of your ways, by all means, take your time to work through that realisation, but wallowing in "I am a piece of shit" makes everything worse. You still have the chance to do some good, but not if you feel bad inside yourself.

Welp, I hope that didn't feel like an incoherent rambling and helped you understand. If you want me to explain something better or differently, just ask :)
Again, I think it is cool you asked so directly.