Why would you stay? What do you have to lose if you start looking?
Most of my reluctance to leave a bad job has come from two places, not feeling like I have enough to invest in looking, and fear of rejection. I don't know if those two apply to you at all, but I'm going to address them anyway :). To the first, right now you are probably unhappy and stressed out because of all of the reasons you outlined above. If you can reduce some of the things that contribute to that you will be a better person outside of work. Taking some time now to invest is worth the return.
However this is where the latter has stepped in for me in the past. There is no "4 easy steps to over coming the fear or rejection". If you go looking for another job you will get rejected. Maybe quite a few times (unemployed for 18 months with hundreds of applications for me). The reality is that if you don't try, apply, interview you won't be any better off. At some point you have to decide if you are worth taking a chance on and do it.
On the positive side, you already have a job that is paying your bills (maybe not well, but on some level enough). This means you can go into interviews knowing that you can afford to turn them down. You have power in the process. You control whether or not you take the job. If it feels weird, it probably is. If something feels off, it probably is. Move on. There is too much drama in the world that you can't fix to take a job where you can't avoid said drama.
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