Do I stay in a job where I am unhappy for 4 more months when the job ends or do I leave at the end of the month and look for a new job now ???

Stay in the job and look for a new one now

Unless you can afford it, I'd stay in the job and look for a new one, then resign when you find one. Jobs are like the opposite of relationships. People find you more attractive to hire when you are already in one lol.

look for another job now so you're ready to leave when the time comes

Pay rates and opportunities will both firm after the start of the year ... giving you more choices and a likely pay increase ... take your time, play for both

You don't quit a job until you have a new one to go to.
Is a reason why you would stay for another four months?

I would stay for another few month's

There are no wrong choices.

look for a new job

Yep