Hello expanding,
I think there is a karpman drama triangle going on with your peer group/family.. you slowed down your drinking, and it sounds like you spoke up about some troubling behaviors of your ex. And everyone is helping him stay with the status quo. You changed your behavior and they are all working to keep the old system going.
The other game at play is probably denial.
http://www.bma-wellness.com/papers/A..._Lies_Rel.html
So I actually think your perception is probably 100% accurate.