As already mentioned, what you're experiencing and describing is more than likely "just" you being depressed about the diagnosis, which is a fairly natural thing - even nowadays, a diabetes diagnosis, especially at a younger age (which I assume is your case, given the mention about studies), is still often perceived by us as very life altering in a negative sense, with visions of the things you might never be able to do again or foods you might never be able to eat again and with a constant image of severe diabetes complications in one's future, or possibly even an early death. The mind is struggling to deal with it and in response, you feel "depressed". I think most diabetic people can very well relate to that and remember how ****** they felt at the time of their diagnosis. I know I did, and I basically knew for several years in advance it's coming (and tried to postpone as best as I could at the time), so I had plenty of time to deal with it. It still didn't help not feeling ****** about the diagnosis.
That said, it's unlikely you're truly "suffering from depression". If you were suffering from a depression, chances are you would've already suspected that before, or possibly even downright knew. Actual depression is a long term thing (and is even defined as such medically). You could kinda say it is, in a way, diabetes of the mind, in the sense that it's there, affects your life and is unlikely to ever be fully resolved (though it can be very well managed to the point where you won't even know it's there anymore). It's where you feel "depressed" for weeks, months or possibly even years on end, and through all that time, you're struggling to find any enjoyment in life and/or in any activities, it makes you feel isolated and alone (even if you are not), misunderstood by everyone, possibly even hated by everyone (and most of all by yourself) and really don't feel like anything is worth doing anymore. It is a truly debilitating condition that will absolutely affect your life, frequently your work and/or studies and have serious consequences in various ways (obviously). As mentioned, though, it can be managed pretty well, provided one decides to seek help. Most people who suffer from depression will probably tell you that once they found effective professional help, it turned their life around in ways they couldn't even imagine before. And they will probably also often tell you that their biggest regret now is that they didn't do it sooner and suffered alone for no real reason.
Anyway, hopefully you're "just" (and please note the quotation marks, I'm in no way trying to make it sound like it's no big deal) depressed about your diagnosis, because in that case all you might really need is a bit more time to think and to consider your life going forward. As mentioned, it might feel like your life as you knew it essentially just ended and you're facing a shorter life with a nasty disease, but that's really up to you. It's a cliché, but it's true. In a way, your life as you knew it ending might even be a good thing, because there might be something you were not doing right that helped (not caused, but helped) to get you to where you are now. And so you have a great chance to turn it around. Diabetes doesn't have to be the lifetime sentence it might seem to you know. It might be an opportunity to live a healthier (or at least a more health-conscious) life. You might start health related activities that you might've known were good for you, but you always felt too busy to do. You might (should, really) think more about what you're eating and how you're eating. You will be more aware of your health and as a result might get earlier warning about potential issues that could present themselves further down the road compared to non-diabetic people. And as a result of all that and much more, you might actually end up living healthier and longer life than you would've otherwise. It really is not the lifetime sentence it might seem at the moment. There is also plenty of people here (and not just here) who basically managed to "reverse" their diabetes completely. And the big scare that for many is insulin injections? Even if - and that is a big IF for a Type 2 - it is indeed destined for you somewhere in the future, it's nowhere near the big deal we imagine it is before we have to deal with it. I was always terrified of that option and couldn't imagine ever giving myself insulin shots and generally living like that - and then I had no choice but to do it right after the diagnosis because I had to first wean off certain medication that was counterindicated to the usual oral diabetes medicine, and it was not in the slightest how I always imagined it. It was effortless, comfortable and without any real issues. I obviously don't want to get back on insulin, because why would I want to when there are other options, but the thought certainly no longer scares me as a Type 2. Type 1's have it more complicated, and even they still manage just fine.
To end the draft of my new novel

, it really is fully in your hands how living as Type 2 will be for you. It doesn't have to be depressing or bad in any way in the slightest. You will have to make a bit of conscious effort to take control over some things in your life, but if you're willing to, you will hopefully realize that it can indeed be a new opportunity for you instead of a drawback you probably might consider it right now. And you don't have to do any drastic changes overnight, too. You can start with some changes and slowly build it all up as your mood and motivation improve. It is, after all, a long distance race and not a sprint, so it's perfectly OK to start slow to better pace yourself.
Apologies for the long post (full of what I'm sure reads like motivational drivel, but it is an absolutely honest description of how I see it at this point in time, having first-hand experience with both diabetes and depression in my life).