Life is too short to stay in a job you truly hate. If you're unhappy, don't let money alone be the only reason you stay. Quit if you need to; this is your happiness we're talking about. No job is worth sacrificing your health, happiness or well-being. If these tips to love your job again simply don't work, simply know when to walk away.
Through experience I believe a healthy mind, body connection is the ultimate step towards happiness. To finish I'll leave you with a thought: If you're physically very fit, are you consistently mentally in a good place to be present, accepting and judgmental to enjoy the benefits of a fit body? If not what will you do about it?