I am not telling you to inhibit thoughts or feelings. I am asking that you become aware of those you have. Realize that they form your reality. Concentrate upon those that give you the results that you want.
If you find all of this difficult, you can also examine your physical reality in all of its aspects. Realize that your physical experience and environment is the materialization of your beliefs.
If you find great exuberance, health, effective work, abundance, smiles on the faces of those you meet , then take it for granted that your beliefs are beneficial. If you see a world that is good, people that like you, take it for granted, again, that your beliefs are beneficial.
But if you find poor health, a lack of meaningful work, a lack of abundance, a world of sorrow and evil, then assume that your beliefs are faulty and begin examining them.