What I need is a way of controlling his temper so I can finish my course.
There is a way to do this, sort of. If you do whatever he wants, and devote a significant amount of time to anticipating his whims, and never assert yourself, and walk on eggshells around him, and live your life in constant tension and fear, and acquire lifelong mental scars in the process... he may not hit you very often. But if he senses rebellion in you, or if you try to control anything, or he simply feels you aren't as cowed as he would like, he will hit you again.
The purpose of his temper is to control you. You can't control it, and I would bet that his violence will escalate as you get closer to finishing your degree and not "needing" him, because the goal of his violence will always be to convince you that you need him. And look - it's working. You're convinced that it's better to tolerate him hitting both you and your kids than to be "in poverty".
You will be able to think much, much more clearly (and earn your degree more easily, I'll bet) in a place of your own where nobody ever raises a hand to you, and where you know that nobody ever has justification to do so. If you have to postpone your degree for a while, so be it. People have lived through worse many a time, and I would honestly make priority one having 100% less violence in your life, because there is no underestimating its toxic and pervasive effect.
What do you need to take that first step? What if you challenged your belief about the terribleness of poverty and joblessness and began looking into what it would actually entail to be on your own? What if you spoke to Women's Aid and could get their help in figuring out a plan to be out ASAP?
In the meantime, please do stay safe - I'd suggest using incognito browsing to read this thread and/or making sure you clear your browser cache of anything about DV/abuse/escape you look at.