Laniakia I'm sorry to hear about all that is going on with your DD, it's stressful enough just going to university. They might be all grown up (in theory) but you still can't help feeling like you want to take the illness and upset away for them.
We had DS last year who didn't engage with any social media chat at all and was fine and Dd this year who is the opposite! I'm sure both approaches will work, they are both very different characters.
We are going to have three years of two dc at university to help with at the same time, as DS is doing a MSC, so four years and Dd starts this time. Ouch - the joy of having 18 months apart dc in age.
Last year, and with halls at Lancaster being (relatively) cheap, ds's maintenance loan just about covered this cost and we stuck £50 a week in the account in term time, to cover all costs apart from his phone (£12 per month). He'd saved money in the summer by working and there was also other monies he'd accumulated over the years. He's extremely low maintenance in terms of social life and drinking etc, so got by on less than this. I don't give him any money when he's at home.
I'm not sure what to do re Dd yet as her accommodation is a lot more, I'll possibly leave her with her loan (minimum) and pay the halls, I need to think about it! She's also worked all summer but has probably spent more socially than her brother too.
Luckily, I have an endowment policy (remember those?!), from my first ever house that is due to mature in October (woefully underperformed its expected value) which we always kept paying as the 'university fund'.
We've just done a Home Bargains swoop for university stuff...