Any time you don’t feel good, use that as a sign to explore your thoughts.
What are you thinking that makes you feel bad?
Which thought(s) brought you down.
Identify these thoughts and change them.
Replace the thoughts that trigger negative feelings with thoughts that trigger positive feelings.
(Or at least feel more neutral.)
It’s not hard. It just takes practice.
“Your thoughts determine how you feel. If you change your thoughts, your feelings change.”