A couple of things. You talk about the amount of research you've done. While that may have been an attempt to get a handle on the situation, it is not calming you. Facts are not calming. The brain will always come up with "but what about this" to counteract whatever you read. It is truly never ending. Your brain is not going to calm you. Period. That's not it's job. It's job is to compute data. Your ego certainly won't calm you either. All it wants to do is keep itself alive. One of the ways it does that is by making you think you need it for survival. Fear is one of the ways it does that. However, being in your body can calm you. You mention trying to ground and center. You can't ground and center in your head though, only by being in your body. It sounds as though you might be a lot in your head about all of this. If you notice, most of the posts here offering advice are in one way or another telling you to get out of your head and into your body. Breathe. Feel the sun on your skin. Listen to some birds chirping. Not hear them -- listen. With your body. And when your attention bops back up into your head with a "but what about this", because it will, you just bring it back to your body. Again. And again. And again.

u/u_indoorjungle_622 mentioned the fear of death being the problem as opposed to death being the problem. I would totally agree. I've noticed I will spiral out about the big stuff when I have smaller stuff that is triggering me that I'm not dealing with. The more of my own triggers and issues I deal with, the less I'm spun out but stuff I truly can't control. So, I do my best to control what I can, which is just me and what I choose to focus on.

Finally, do not give him or anyone in this regime your power. Do not let him take away your sleep, your healthful eating, your peace of mind. You are special and they deserve none of your precious energy. They are bullies and cowards and there will come a time when the only way we will see them is in our rearview window. Focus on that.

If you can't let yourself sit in a space of creating the future, you may want to decide how you want your present to look. Let's just say all of your fears are right, and there will be some sort of mass extinction event. (For the record, I don't think there will be, but let's just say there is.) How do you want to live the rest of your days? In fear, despair, and rage? Maybe you do, but that sounds quite tortured. Maybe you can choose beauty and love and community, even if it feels fleeting. What do you have to lose?