I think it's important to remember that when you tell friends you've quit drinking to not expect them to know what to do. If they don't invite you out it might not be because they're dumping you for being "unfun" but it could be that they're worried about putting you in a difficult and awkward position.
One of my best friends where I live made a decision to stop drinking in the time that I've known her. I didn't know when I found out if that meant she'd no longer want to go out with me and our mutual friends. It was she who came forth and made it known that she still wants to hang out even when alcohol is present--the two of us just have our sodas or whatever and enjoy the company of our good friends.
There were some friends I did more or less stop associating with when I got sober. The near entirety of our social life together was going to a bar -and- getting plastered. It's possible I could've just hung around and not drank, but there was so much emphasis with them on getting drunk that I couldn't see anything left for me.