If you'd rather be on benefits than in this job, maybe this can help you not to stress so much about it? I mean, the worst that they can do to you at your job is fire you! If you are not afraid of that, then what's the point stressing?
Try not to let the job get to you, just take it easy - work to rule, don't agree to overtime, don't rush for deadlines etc. If you get fired, you'll then be able to get benefits while looking for another job. If you don't get fired, at least your life will be more bearable, with stress reduced.
Some years ago I had a terrible job that I didn't want to quit just yet (as it had been hard enough to get even that) - I decided to stay in the job for a year and then start looking for another job. It helped me to draw a small line on our living room door when I came home from work, then at the end of the week I would put a cross through the lines for that week and feel one week closer to the time I can start looking to get out
Maybe it sounds strange, but it did help me to keep going