A couple of jobs I have had come to mind when thinking about employees and bosses. One boss was the son-in-law of the owner and he was an idiot and a jerk. He hired people that basically didn't work and I ended up taking care of their load. The way the business operated was a joke although I liked the work itself. I started getting stomachaches and decided to leave that job. Another job, the benefits were great but it was stressful. I started getting heartburn really bad and put on prescription drugs. I quit that job and went back to my old one. Both times I quit I had no more stomach problems. I don't regret quitting either at all. Yeah there are always a few idiots at almost every job but one has to look at the whole business operation. Also, a person spends most of their time working. Even if one gets 4 weeks vacation, the other 48 weeks is spent at a job a person might dread.
Jeremy, it sounds like you like the work you do, just not the way business is handled. This ex-worker obviously knows your a good worker and would appreciate you I think. He has had the business for 5 years and most new businesses close within 1-2 years. As an insider at your job, you see where things are heading with the company. This guy is will most likely pick up the old clients and continue to grow. Maybe take some time to think about things and maybe take a little vacation time if possible. I would wait to see what the doc says too before making any decisions. I hope you feel better and please let us know how things go.
"An ignorant man thinks he knows everything, a wise man knows he doesn't."