I was diagnosed with ADHD when I was younger but I'm pretty sure it was just my bipolar disorder manifesting itself. I still take the meds
I think that's an issue with ADHD/ADD, it can often actually be bipolar, which usually doesn't fully manifest until 18/19 (it may have been 20 for me). However, depression is not usually associated with ADHD/ADD. What you're describing, such as not sleeping/eating well sounds more like mania to me, that coupled with depression sounds more like manic depression. Not that I'm a doctor or anything, just someone who has it (and is studying psych mind you
), and didn't realise it until I did some research and started to track my mood/behaviour over a span of several months. Just something to look into, because if you're going into university it may not really be easy to make yourself focus on things.
Hope that helps.