Lots of people self-report improved mental clarity, focus, and cognition on "clean" diets. Food can have a big impact on brain health and mood.
If your diet isn't great, now might be a good time to clean it up: cut out processed foods, sugars. Go whole food only if you can
If you are in a one-on-one back and forth conversation, and your partner is downvoting everything you post, they are not having a good faith discussion with you.
It is a fuck you. Why spend time and effort on someone just throwing negativity at you?