You want to get a copy of the book "Feeling Good" by Dr. David Burns,

It is about how to use cognitive therapy for self help. Cognitive therapy has been proved to be as effective as medication for may psychological issues. It is based on the idea that our thoughts cause our emotions.

You are told you won the lottery, you feel great. You are told your favorite TV show is canceled you feel disappointed.

Cognitive therapists state that many of our thoughts are not completely rational, that there are other thoughts that fit the facts better.

So, if people are feeling negative emotions cognitive therapy would help them articulate those thoughts, analyze those thoughts for how they are irrational, and replace with more rational thoughts that also fit the facts but that inspire less negative emotions.

Many people on reddit swear by CBT and state that it is like jogging. You have to do it consistently, every day, or several times a week, but it does work.

Good Luck.