First of all, your arguments are all strawmen.
Changing clothes is nothing like believing you are something you can never be. Someone who is a biological male believing they are female is a delusion. Like someone thinking they are a toaster. It is not real, it is a delusion brought on by a mental condition. Similar to schizophrenia.
As far as changing your genitals, go for it, that is your right. Though I believe self-mutilation is also a mental illness like wanting to cut off your arm for no reason. It still doesn't change your biology or gender. Similarly, dressing as the opposite sex does not change what you are.
Also, you are misusing the word gender. The gender of a species defines if it is the male or female of that species. Like a male deer is a buck and a female deer is a doe, and a male horse of the equine species is a stallion and a mare is the female of the equine species. Likewise, a woman is the female of the human species and a man is the male of the human species.
Gender is not "fluid" or a construct. It is a defined term used by biologists, anthropologists, and science in general for centuries to define the male and female of a given species.
You don't get to change or redefine the lexicon to fit your narrative.