If you simply wanted to bolt from China, never to return, your options would be wider. But because you want to return to China, you want to minimize any bridge burning.
I should first point out that your Residence Permit, (RP) is tied to your employer. If you told your employer you were leaving, your employer would be obligated to have your RP canceled by the PSB and an L- (tourist) visa issued in its place.
You would be working illegally if you simply skipped out on your employer with the RP in hand. For one thing, after your RP expired, you'd very likely need to present a letter of recommendation/release to obtain a new RP. So I would strongly recommend against that course.
Your best bet for a smooth transition is to approach your employer and explain the situation. Your employer will not be happy, of course, but you could take the sting out of the situation by helping recruit and train a replacement, offering to stay on until a replacement is trained, etc.
You contract will also likely include monetary breach of contract penalties that you will need to negotiate and, ultimately, likely pay.
What you want to exit this situation with is a letter of release/recommendation and having your residence permit transferred to your new employer. To do that, you need to negotiate, and have both your current and new employer cooperate with each other to transfer your residence permit (a simple process actually).
When you explain the situation to your employer, explain why you feel you must leave and what you want out of them upon your exit. Then ask them, what they need in order to deliver that.
You cannot return home and simply get a tourist visa and return to a new employer. Your RP is in the PSB database and would almost certainly be flagged for an explanation, and you'll still need a release letter.
I would suggest you really steel yourself and see if there is any way you can bear to finish your contract. The holidays are upon us which should lighten your spirits as well as your workload.
You might also discuss shedding some of your hours and responsibilities during the remainder of your contract if you cannot negotiate a smooth exit.
I wish you well.