can't find E-85 gas anymore.

What is your question?

I live in 11706 area code. I have a 2013 Flex-Fuel Dodge Grand Caravan. All the gas stations that sold E-85 gas don't sell it anymore, why? And I've been using reg gas since, will it harm my system, it's been over a year now. Should I start using Super or Premium gas?

What makes this problem better or worse?

Depending were I get the gas, sometimes car shudders and rides rough even while idiling.