Sounds like stress to me but I'd check your diet while you are at it. It's not the feelings that cause us the most trouble but our thinking. "Despair" is a thought, you have to define it and quantify it, etc. and that's all thinking and digging a deeper, more comfy nest for it. Start thinking you are feeling better and going in that direction and eat some protein an go do something "interesting", even if it is still related to your session and its difficulties; just note them as if they happened to someone else so you don't fall into feeling about them.

See your avatar? The spiral goes both ways, tighter and tighter (like your headache) or open and out. . .