My opinion: It's more important to have a job you enjoy than a job that pays well. No amount of money is worth risking a mental breakdown due to job stress. I would really try to reflect on what the new job has to offer (in terms of reduced stress) over your current job, which from reading your post it seems like you've already done this reflecting. If the new job offers the opportunity to reduce the stress and the physical harm you're experiencing, then I think it is well worth the pay cut. But if it's going to be just as stressful, then why switch? Unfortunately you won't know what the true stress level of the new job would be until you actually start working that job. But based on your description, I'd say you're better off with the new job.
My wife had a high-stress job that sounds very similar to your current job. The stress was deteriorating her physical and mental health. She FIRE'd about a month ago, and she is a whole new person. The pros of leaving her job far outweigh the loss of income.