How do I recover from burnout?

I'm in such a pickle. I work in admin/call centre and I feel like I'm having a constant panic attack all day.

It's not even a high stress job, however, my only other co-worker dropped her hours last year which means I have no one to share the workload with half the week. The people who have been asked to help out during this time either flat out refuse or do the bare minimum.

I've reached a breaking point and any communication with my manager, results in maybe a week or two of improvement and then it's back to square one.

I've been applying for all sorts of jobs with no luck and really don't know where to go from here. I know I can't afford to be picky but the thought of going to one terrible job to another has put me in some sort of paralysis and I have no energy. It's got to the point where every tiny part of my day triggers anxiety, even the parts that never used to.