How to re-set my eating habits to feel better

[Cardboardfish]

Hey everyone and Happy New Year! smile
I am looking to re-set my current eating habits in order to improve how I feel. I have Ankylosing Spondylitis and eating well definitely helps me manage my symptoms.
I am looking for any advice or recommendations of a healthy, nutritional eating plan that I can follow that isn't heavily focused on weight loss. I am in my 40's and am very active. I play squash 2-4 times per week and see a Personal Trainer 1hr per week.
The problem is what I am eating. I know i am not fuelling my body properly but I am overwhelmed by all the information out there online. I spend hours looking at recipes etc but not sure how to apply this knowledge and when to eat the different types of meals etc.
What I would find useful is a more personalised nutrition/meal plan to accompany my current fitness regime.
Any ideas or recommendations?

Have you considered rhfitness, short version you wear a heart rate monitoring device eg Fitbit this tells how many calories you burn
You decide your goal eg weight loss/maintenance/clean bulk then eat set number of calories divided into protein fat carb MyFitnessPal app helps with this

I find it good, it showed me I was under eating for amount of exercise I was doing