Most academic institutions have someone or a group of staff whose job it is to help students with various disabilities. I suggest you talk to them and to your departmental administrative staff to find out what is provided and discuss what your needs might be.
If there is an inadequate choice on the menu in the various student eating places on campus you may be able to request special meals be made up for you and kept separately. I know that if you are on a small campus this is easier. You could also find out who the catering manager is and talk to him/her.
Most staff will not know you are a diabetic unless you tell them, confidentiality will mean they don't pass information around. Even if they know they may not be empowered to tell others who are the ones who might help you so it is up to you to talk to the right people.
For those who think students should be suddenly adults at 18, remember that until around 1970 they were still classified as minors until the ago of 21 and the universities were in loco parentis i.e. legally acting in the place of parents for most undergraduates.
Having said that their parents should ensure they can cook, do laundry and clean etc. before they leave home. This should mean they help with chores around the house as a matter of course every day from the time they are little.