If you allow a negative thinking style to contaminate your mind, the dark side will prevail.
The remedy is not to ‘think positive’, though that can help, a bit. The answer to pervasively negative thinking style is to change HOW you interpret events, not WHAT you think.
If your natural thinking style (explanatory style in psycho-speak) is pessimistic, and you use the same style or outlook for everything, then your thinking like Eeeyore, and that’s not the best way to go about things.
Still, I would say that, wouldn’t I because I’m an optimist.
Whatever way you choose, may the force be with you.