[TheAtomicBlade]

Hey,
I know how you're feeling. I'm going to give you a bit of rough love. You need to move on. She didn't give you happiness, you gave that to yourself.
I've not been in touch with some of my closest friends because they are busy. It hurts like crazy. I feel super alone too. But I've started finding things to keep myself occupied. I listen to music, go for runs, workout, and do other things to keep myself occupied.
You need to find that click for you. Its going to be hard yes, but you can find it. I've got depression too mate, due to causes I'd rather not discuss, but I am trying to find things to keep my mind occupied.
I understand this is a rough patch and that this friend meant a lot to you, but you can't let it destroy you. Something similar happened to me (albeit not with a very close friend) and it did hurt. But you need to move on. You need to find closure in some form.
Perhaps meeting a therapist is something you can consider to try and find closure. Or perhaps you can try journalling, or working out. Working out is great since it releases endorphins making you feel better AND as you shape up you feel better about yourself.
Also, perhaps you could look into social networking to meet new people. Perhaps use the app Bumble (you can use it to find friends) or websites like meetup.com. If you're at uni, perhaps look at some clubs and social activities they hold? Those are generally great places to meet people. Or perhaps look into a class like yoga or meditation which helps bring peace and also meet new people.

Hope this doesn't come across as attacking you, I promise thats not my intention. I'm just trying to help you get out of the rut.
Keep your chin up it will get better.