Hi Emily,
Big big hugs!
Of course you can go to University - once diabetes is your partner, not your enemy. It may take you a little longer than you'd hoped but that's a good thing - the best students are often the ones who've had a bit of life experience outside school, so not going now isn't really a bad thing at all.
Relationship breakdowns are the pits! I think many of us on the forum will remember how it makes you feel that life's not worth living so why bother trying to test, inject, eat, wash, get up, speak to anyone . . . But you have, you've spoken to us, so hang in there and know that you're not alone. I hesitate to use the old cliche that it'll get better, even though it does, because it seems so trite and uncaring, but like all cliches it's lasted because it's true.
Now I'm going to be a tough old woman! (See, I've lived a long long time with T1, I've come out the other side from breakdowns, from a few ups and downs, and the ups have been worth it!)
Get yourself to a surgery (sounds like a bad version of what Hamlet said to Ophelia, doesn't it) and take the first babysteps towards a better future. Ask for help. Listen to what's suggested and ask, too, for the support of a DSN, a nurse who can help you with diabetes. Don't beat yourself up if it sometimes goes wrong, and celebrate if you feel good when your blood sugars are more or less ok.
Are your family supportive? Ask for their help too. Get as many people as you can on your side.
Life with T1 can be good and you CAN have a future worth getting it right for.
Go on talking to us, tell us what's happening.
More hugs.