Hemorrhoids are nothing but aggravated kapha structured with vata-pitta. and the best way to beat hemorrhoids is to include buttermilk and Elephant yam (suran). so try to include them as convenient to your GUT and as much as possible. Mostly, if you do this for next 6months your surgery would be avoided.
Also, don't worry as there is no very perfect diet for everyone,and again everyone dietary needs from day to day differ. but always homemade food and our cultural diet varieties have been found the most suitable to one's GUT flora. so as far as possible stick to your culture-made home food. don't junk.
your other issues, needs consultation. so do consult a good ayurveda consultant for that.
Next Steps
consulattion
Health Tips
avoid vata-piita kar ahara and vihar