For what it's worth - people starting uni all tend to be quite nervous and worried even without mental health issues. I mean it's a big step for everyone, right? So actually in those first few weeks where everyone's finding their ground, they probably won't even notice you have MH issues. Bond with people in that opening period where it won't be as noticeable if you struggle from anxiety and depression or the like...if you can. It's not that easy, obviously.
Still, as people have said - there is support available. As a generation we're generally quite anxious and depressed people and universities know that, moreover have to be prepared to help with MH given the sad levels of suicide that sometimes occur. Seek them out once you start, and try to register for therapy/other professional help at a local doctor's once you've moved in and set up for a couple days.
Most importantly...don't give up.