IBS-C and what to eat

I am in my late 60's and have dealt with GI issues for many years.
I don't have the best nutrition--between food not appealing to me, and being scared of certain foods that have caused me problems, I just don't know what to eat. I am not losing weight, but some days I don't eat much.

I have GE reflux, and gastritis. I've not gotten very far with my GI provider. I've thought of seeing a dietician or nutritionist. I'm thinking I need to keep simple meals around and eat them whether I want to or not.

Anybody else just not interested in food anymore?