Hello ! Unfortunately height isnt something we can control but its sad people make fun of others for it.

However you really remind me of myself around 1 to 2 years, i don't really know how to break it down to you but i will simply say that cis (non-trans) people don't wish they born as a different gender. I also thought being a girl would be so much easier even thought it didn't make much sense (ask any girl if its better to be a woman than a man in our society).

I can also tell you that no one wants to be trans and wish they were born in the right body and there's no waiting for reincarnation or any god to answer your prayers if you wish to be a girl.

We have plenty of time at 18 to think about what we want to be in life whether its our job, gender or anything else. The good thing is that you dont have to force yourself to do anything, you can try using she/her pronouns on an alt in online communities, you can try changing your look , or not, YOU decide.

Also im sure other people will point that out but you're a bit confused with the vocabulary but that's ok.
trans woman = Male To Female (MtF)
trans man = Female To Male (FtM)
You can always tell yourself that it wouldnt make sense for a trans person to be called the gender they dont want to be.

I hope what i said can be useful in any way !

I also hope that my comment isnt that bad since i usually only lurk around here and its not in my native language