[johngalt]

Don't listen to your brain. It will give you a bunch of reasons to be sad, and ruminating about it will only pull you in deeper.

Ensure you have enough of the following: Sunlight, physical activity, sleep.

Set a specific time to sleep and wake. Get a step counter and ensure you are getting at least 10k steps a day. Regular walks during the daytime will help with both sunlight and activity.

After that, work on diet and social activity. If that doesn't fix it, talk to a professional.

[leros]

I completely disagree on not listening to your brain. Your brain has an emotional side, some call it your inner child, that is the raw unfiltered you. You inner child might be screaming out for help because he doesn't feel safe and needs your help. That is worth listening to. You don't want to just grit your teeth and ignore your worries.

Your feelings are completely valid and there is a reason you have them. Don't ignore them.

That being said, you also don't want to let your brain run away and make you miserable with repeated worrying. It's a balance to recognize that you feelings are real, deserve to be recognized, maybe require action, but also to not let your worries dominate your life.