I want my ex girlfriend back and she claims she still likes me, but how do I do it?

How should I go about this? She is claiming that she can't be with me because of her depression. She is on medication, but I don't see it as helping since she has been on it for about 4 months. Likewise, she sees counsellors pretty much weekly but again, nothing seems to be helping and she doesn't look like she is getting any better. She says if she gets better she would like to be with me again, so therefore she is still attracted to me. When she has a good day it is apparent she wants to be with me, and she is so loved up, but when in a bad mood she will just argue and be really stubborn and hard to talk to. I love her so much, we dated for about 3 months and then on and off for the past month or so. She claims that she thinks by me being in a relationship with her its making me upset, which in turn is making her more upset, so she said to me yesterday we shouldn't talk till the end of the Summer (she goes away on holiday in 30 days for 2 and a half months so we would talk when she gets back). I know even now she is probably missing me because of all the stuff and memories we have, her room is full of things I've made or bought for her etc. So I know she is still attracted to me, but I need her to know that I want to help but I want to be with her so badly. Also, when she is in a relationship she feels she doesn't do enough for the other person so that makes her feel worse too. I will struggle to not talk to her and I know she will too, but is it best to let her miss me and reevaluate her life, and maybe realise that she wants me in it? What should I do? Thanks.