Italian catholic here too...not sure if the guilt tripping is unique to that ethnicity, but I do relate to what you posted. My sister and her husband pretty much shut me and my wife out for a while because we are teetotalers and they wanted to be in their cups on the holidays. Two DUI's later on my brother in law's part and suddenly we're more in demand, now that he's trying to stay sober.
All I can say is don't take it personally. People who are using are under the spell of the substance. I know I was. The booze takes top priority for the active drunk. Sad but true. You should be glad you don't have to put up with it.