Hello, sinking. Have you thought about therapy? Cognitive Behavioral Therapy deals with cognitive distortions and automatic thoughts in an attempt to challenge and positively modify the negativity you speak of.

The links provide much more information:

In-Depth: Cognitive Behavioral Therapy | Psych Central
Psychotherapy - Psych Central

More information:

15 Common Cognitive Distortions | Psych Central
Fixing Cognitive Distortions | Psych Central

Change is required to help you manage the negativity and achieve a better life. Good luck.