Have wewe ever had a friend that you've known for, let's say, 16yrs, and all of a sudden they started being a total ass?

I'm sorry for you! I've been through a bit of the same thing. I'd be a cliché if I'd told wewe wewe could do better and stuff(not saying wewe couldn't, but let's stick to what I want to say). You're right it sucks but wewe should talk to this person. Let him/her know how wewe feel about it but first keep your emotions together. When wewe start talking let them know wewe still like them(even though wewe might not even do so. but trust me, it's better). Then when he/she still hasn't aliyopewa wewe the reason why, confront him/her with everything that's on your mind, and then let your emotions go free. It worked for me, so I hope this helps.

And when this person doesn't stop becoming heartless and insensitive, don't think too much about it. If wewe know the how and why about this person's changes, let it be. How bad this might suck, there's nothing wewe can do about besides talking it out. Sorry!

I hope I could help!