It doesn't matter if you "believe" it, transgenderism is not subjective and it is not a choice. Period. It's a medical condition that occurs in the womb. Anyone who "decides" they are trans is mentally ill and it doesn't require your faith for that to be the case. Just because the pharmaceutical companies that sell estrogen want you to believe it's a choice doesn't make it one. If you really believe people can "decide" to be trans you are not only hurting the actual transgender people by promoting the troons as "valid" (they aren't), you're also promoting pharmaceutical propaganda. I am a very empathic person and I pity people who fall victim to this ruse, but just because I care about them doesn't mean I have to validate them. And as far as your "fallacy" goes, no true Scotsman doesn't apply when you're talking about factual medical conditions. You can't identity as having cancer, you can't identify as having fetal alcohol syndrome, you can't identity as being trans. You either have the birth defect or you don't. It isn't a fucking "feeling" thing it's a medical condition.
Validating someone for being trans when they aren't HURTS THEM.
because it prevents them from addressing the actual issues they have.
I'm sorry that it makes you feel bad, I'm sorry that it seems "mean", the fucking truth isn't nice. Do you want to live in the real world or your fantasy world? I'm sorry, it's time to grow up and face objective reality.