I wasn't trying to make it sound simple, and I'm sorry if that's how it came across.
I meant that you need space to sort your own self out before you can be a shoulder to her, because neither of you sound like you are in a good place right now. And it is really hard to do, because you would naturally be used to being there for each other.
I had the same problem with my ex, because I was his only friend (literally), and he had been my only support through an eating disorder. It seems counter-intuitive to back off during such a difficult time... but, from what you've said, she needs to find other forms of support too, and a bit of space might encourage her to do that.
I may be completely wrong, but in my own case, I regretted not taking that step back, and it took me much longer to get my head straight afterwards.
If she's going to university, that's a great opportunity to make other friends for additional support. A lot of unis have great counselling services too
Some people find that, gradually, they start enjoying the hobbies for longer- maybe that will be the case for you
Or just anything that can distract you for any time at all. If you can just 'get by' at the moment, it will (believe me!) start to get easier. Do you have people that you're close to, to share any of your feelings with?