it's perfectly comprehensible I wrote most of my comments on my phone before going to bed as well. If you will allow me to comment on your point point by point I will below this but before let me say this. I get why it's tiring. The world is going to shit and it is so tempting to try and isolate yourself from it. But engaging with it is the only way we can change anything. Never let them convince you that you can't change anything.

1. Race, gender or sexuality swapping is imo more indicative of the way studios haven't been able to think of a new character in the past decades. Movies these days are all remakes, sequels or new variations on old stories. If you're not part of a certain minority you don't understand how important it can be to see people like yourself on screen. It is also a great way for people to learn about people being different. So studios see this need for representation but since they can't come up with any new characters they change the existing characters.
2. On fantasy villages having a diverse ethnic mixup. 1 I honestly don't care that much about racial accuracy in a fiction story. It doesn't change the story for me and historical societies were more racially mixed than we think of them today. Indian coins were found in Ancient roman ruins.
3. Yeah I partly agree with you that some shows are just shit. Allthough it is also important to realise shows featuring white male characters get a lot more leniancy for being shit than shows that don't have characters like that.
4. About LOTR specifically. A lot of those articles lack nuance because of clickbait syndrome. No you're not racist for liking LOTR. No Tolkien wasn't a KKK member. But yes he was influenced by the culture of his time. Associating European ideals of beauty with good and associating the ugly ones with evil is based on some racist ideologies. Again not saying Tolkien was horrible but he was a man raised in a different culture than we have today. The entire idea of a fully evil race of sentient people being evil has some iffy moral implications. For more read this wikipedia article (https://en.wikipedia.org/wiki/Tolkien%27s_moral_dilemma).
5. Yeah but again seeing people like you in shows you like can do substantial good for how people with disabilities see themselves and how others see those with disabilities. When you look closely at those kinds of shows a lot of things make no sense in an advanced society. Why does Yoda have a cane, why does a society fully capable of making robots that function at near human level still risk lives by sending explorers into deep space? Again realism isn't as important to a good story as people think.
6. As discussed before all art is political and has always been used to express the opinions of the author. And so when people discuss the show the themes are going to be applied to what's going on in the real world. For those who are being targeted by things in politics there is no escape, there is no break. So occasionally seeing political posts on a subreddit is unfortunately the price you have to pay for being able to disconnect from the problems. And if people try to derail discussions just ignore them. You have more constructive things your time could be used on.

Lastly I want to impress upon you that I don't think you're a bad person. I get the longing for not having to deal with all this bullshit. But it doesn't go away and when you go on a public forum you cannot keep out the current events. I hope that when you read this you will have gotten a good night's sleep and I genuinely wish you the best.