I hear you.

For me personally in this situational stress I find that even after positive experiences my mood will drop - usually because of a thought that has triggered me and more often than not that thought (for me personally- yours may be different) is that "I have failed". It only needs to run through my mind once for it to trigger a mood disturbance. Usually now (with practice) I can catch the thought and challenge it before it makes me drop too much.

Are you ruminating causing your mood to drop after positive experiences? It is all about observing your thoughts and checking if they are infact causing this mood disturbance. This happens to me sometimes, not as much as it used to now but I could ruminate like noone else at some stages of my life!

Have you done any CBT? I can honestly say I use it every single day since I first did the group over 10 years ago. Sometimes its not as helpful but for little "blips" and anxiety it is fantastic to help get through and out before they spiral.