The Rollercoaster of Social Anxiety

img source

I've used to be socially anxious as a teen and I have days where I sort of 'relapse' back into that state. I don't know what causes this but on certain days I'm just overstimulated and cannot handle uttering any word to anyone.
There are days where I'm fairly social and thriving and suprised by myself but then I go back to my normal level as if nothing happened, it's as if no progress was made.
The days where I'm thriving socially are sporadic and I cannot find a way to trigger them manually, they're random but I wish those days were my baseline.
Whenever I'm feeling socially confident it's temporary and then I come crashing, it's like that dopamine analogy in comparison.
What comes easy to most people is unnatural and difficult to me and I just can't break through. No matter how much I'm exposed to socializing, how much I get out of my comfort zone nothing ever changes for the long term. To me, social struggle is the worst feeling. I can take almost anything with grace, but failing at socializing just defeats me. I guess it's because it's something I literally cannot improve at. One one day they see me all cheery and shit-taking and the next day I'm a mute.