So I struggle with something similar and it turns out it’s because I’m autistic. Maybe you are neurodivergent too? If you decide to consider this idea, I recommend to check out content where neurodivergent people talk about their condition. I would never consider I might be autistic just using descriptions by neurotypicals, the difference is huge.

Now, about your actual question… I don’t really have a perfect solution. I personally use marijuana. I usually plan the time to take a break from all the projects and learning at the end of the day. I make sure all the important chores are already taken care off. Weed definitely does help but I see how it’s far from a perfect solution. Ideally, you wouldn’t rely on any external substance for your wellbeing.

Many people recommend meditation as a way to regain control of racing thoughts. I was never able to make that work though. Whenever I try I just start working on one of my projects in my head…

Good luck!