recognize this alot aswell...
I tend to be bad at keeping up communication either way nowadays either way, probably cause I don't see a reason to do so anymore :/
As far as msn goes, that protocol is getting rather old, normal people have finally realized that it's not safe to use anymore and/or found better alternatives (facebook being the prime com-channel for NT's and other not so netaddicted folks like us aspies <.<
however, I have some great alternatives to cheer you up with
First, join facebook the safe way (which i didnt do at first myself so I have an "NT account" so that those ppl I have to meet IRL can recognize me there...) and get in touch with your old friends there if you havent alrdy. its the "new" thing/trend in instantmsg communication and its a hell which people tend to abuse to the max. quite funny really... ^^ ppl chat there too
The safe way would be to choose a completly random name, it's easy to fake as they cant check it anyway. sure they have filters and stuff but once you're in you can easily change it to whatever you'd like and then send pm's or emails to the ppl you really want to be "friends" with there. I have a bunch of friends there that I dont have as actual "friends", mainly for security reasons...
Second, find other methods, like the old but well working method of IRC and other chat systems. there you can find both fun knowledge and good friends. and not to forget, admins keep it clean so no bullying and such ******** will be allowed
Third and most important of all! stay here as much as you can and get to know us! we know what you're talking about
While explaining it to an NT would most likely give you false emotions or an unwanted response in most cases (imo and from my experience anyway)
Hope all works out for you, I myself find it most enjoyable to do as many others do, stick with their hobbies and obsessions
however, one good sign has already shown itself, your friend cares about you and announced his action. which many of my own never did... cept those who are my real friends, online that is. =)