I also suffer from a lot of anxiety, & I understand how working out is difficult when one is anxious. For me, I would rather curl up in bed when I'm anxious. So on those days, as often as they come, I try things that don't seem like "working out" It just adds to my anxiety, especially if I can't push myself to follow through.
I'll lift light dumbells or ketllebells while watching tv, I'll go for a walk if the weather permits, I'll hulahoop, or vacuum(it needs getting done anyway!) or dance. I focus more on MOVING, less on a strict "work-out"
Hope this helps! At least a little. Us with anxiety have to stick together!