Are you an optimist or a pessimist? Do you think the glass is half-full or half-empty? It doesn’t matter. It’s still the same amount of water. If you want more water, fill the glass. If you want less water, pour it off.
It doesn’t matter what you think. It matters what you do. You can keep having negative thoughts, but keep having positive behaviors. As long as you’re doing more right things and wrong things, you’re getting better.
Don’t worry about being a pessimist. Don’t force yourself to be an optimist, or even fake being one. It’s natural to have down time, to have negative thoughts. But it doesn’t matter what you think. Don’t just be a thinker. Be a practitioner.