>>2 >>3 If you don't care, DON'T POST ANYTHING! Because for the record, some people DO care.
>>1 I can't say I've ever been in your shoes, but this is the best advice that I can give.
Having a phone number or some means of communication with her is good, but maybe try joining a club or a group of some sort as well. This might sound really cliche, but if you join a club with people with like interests, there's a chance you might just make some really good friends. You don't have to end your friendship with her (as it sounds like she can't just be replaced), but if you make a few new friends, it'll be easier to recove AND you'll have a new strength as well.
Maybe this sounds cliche, but it doesn't mean it's not true. I truly and deeply wish the very best for you, I hope this helps, and I hope that the future for you will be the best.