Really glad you've reached out and shared how you feel. It does seem like you're getting the raw end of the deal here.
Not spending time with each other for a year, being blocked on facebook and steam and being lied to. No wonder you're feeling the weight on your shoulders!
I wonder if it's time to consider whether her actions are of a loving girlfriend or something to let go of.
You mentioned that you miss her and you're lonely. It really sucks feeling like that. I'm a bit like you in that if I miss someone or feel lonely the same thing happens - stress and anxiety and feeling depressed.
In the past I've had to make the decision to let go of something that was a source of pain which would cause pain anyway. The thing with this is that after the decision and some time with the pain it started to lift.
I'm not saying to break up with your girlfriend but I am wondering if you are worth more than being shut out of all but one communication method by someone you're supposed to be in a relationship with.
In your post you describe no longer enjoying things, feeling lonelier, and feeling like you can no longer deal with things. Keep holding on for now neroben, the chat with your counsellor isn't that far away.
There's lots of resources here on the beyondblue website and if you need to talk to someone there's the 24 hour number to talk it through with someone. That's on each page on the website. It's at the bottom of this page.
I feel for you because it's really tough. Try to take things moment by moment for now and just look after yourself, do your favourite things.