Why do i get nervous and specially get desperate and very anxious including mad then change my mind and do the opposite of something positive to -?

Complex: This question cannot be answered without knowing the typical circumstances of when you do this. Also, a knowledge of your history, both medical and psychological is important in helping you understand this. I suggest you consult a mental health professional.

You're conflicted: It would take awhile to sort through all the elements of the conflict - to hear the pros and cons of each combatant. It's a bit like a military action where the voice of each side requires to be heard. When we don't - we fight and suffer and never know why and rarely solve anything. Talk therapy can be a place to resolve the issues by diplomacy. CBT always optimizes medications for mental health.