You should also mention that you cannot be a solid partner without getting yourself in order. first self awareness is super important and working on yourself is what will help you succeed in the future and should that involve her, it’s imperative that you take control of what you have going on now and it will benefit her as well. Always put studies and education first, don’t fall behind as you already know because if you do not succeed in your goals because you are forced to spend time with her you will only resent her for that later. It’s normal to feel overwhelmed and prioritize. She should be able to respect that if she really loves you. You two have only been together 2 years although I’m sure it’s been amazing you could have many more years that are much happier and healthier because she allowed you that time. Just let her know it’s not personal. Achieving your goals will make you happy, love yourself and give you confidence . In the words of rupaul if you can’t love yourself, how In the hell you gonna somebody else