Don’t just quit your job without another lined up. Milk the current company for everything you can while finding a new job. They’ll find a way to offer you the position and pay you deserved from the beginning when you put in your 2 weeks. Don’t accept their crap, find a better job, and move on. I do think you’d regret quitting without anything lined up. I’d just twiddle my fingers and do as little as possible at current company.