I had a boss just like that when I was at uni. This job is for right now, uni is for the rest of your life... seriously, you need a new job. You don't have a 'right' to pick and choose your hours however much that may be really unfair. As you are a student, you can't even claim constructive dismissal as in the eyes of the law you are not dependent on a job until you are out of education.
I eventually gave up on the rotten boss and got some great jobs temping - you negotiate the hours you want and the money's usually better than you would get in a permanent job.