Recurring diarrhea for the past 2 weeks.

I have been having diarrhea on and off for the past 2 weeks. Some days I am completely fine but some days I have runny stool and need multiple trips to the toilet. I get better within a day usually if i eat less and eat non oily foods or curd rice. I seem to get worse when I eat paneer or cheese or any fatty or oily foods. Last night I had butter chicken paratha and 1 pint of beer and today I woke up at 7 am with very runny stool and have been to the toilet 4 times since. I have been feeling better since I had lemon tea and curd rice and ors. But I am still weak and I don't feel fully well yet. I still have a weird feeling in my stomach. Today was the worst since all this started. Could you please tell me what to do...maybe you could recommend any tests I may need to take or someone I could see regarding this?