Sorry to hear that, I have made friends over the internet, I have a firend that I e-mail sometimes a lot then go a few months and not hear from him again. But I just keep sending him messages to let him know I am still around. We happen to post on the same board, and we both have mental health problems. I can understand him, where others might not.
Maybe your friend has a mental illness, too bad she is mixing drugs and drinking. I take Geodone and found that my tolerance to the drinking is high and I just can't get drunk so I gave up on the drinking. Better that way.
Maybe you can just write her back a letter and let her know you are sorry for snapping at her, and if she cares to talk she knows how to get ahold of you. Other then that wish her the best and hope that she can help herself.