For every negative thought say 2 positive things. Accept that negative thoughts exist but they are not you. What we focus on expands. If I think about complaining, instead of actually complaining, I work to breathe through the sensation in the moment (usually only takes a few seconds but one minute is also typical) then say 2 positive things. Can be out loud or to yourself. Thoughts dictate emotions. Emotions dictate thoughts. Good thoughts and positive emotions = happiness. It takes work to be happy. It’s easy to complain and focus on negative thoughts, that takes no additional effort or training. But the more we work to plant those positive thoughts, the weeds will quite literally be weeded out and you’ll see them less and less.
Keep on stepping x