What is going on with me? ?

First off, I do take antidepressants and a mood medication, and yes I do suffer from chronic depression and mood swings. 

Back to it. I am an aspiring filmmaker and I’ve come up with a story for a film I wanna make, and the more see the story in my head and come up with ideas for it, I end up getting sad, anxious and I wanna cry. It feels like the beginning of an anxiety attack or a panic attack. I just can’t shake the feeling every time I go write something down or do any work on the screenplay. I just can’t do it, I can’t get the feeling to go away.