How many calories?

I am 2 months post op and my eating plan does not give me any guidance on calories. How many calories should I take in? How many grams of protein do you have per meal? At the moment I have 30g of chicken, meat etc per meal, but I get hungry after an hour. 

My dr's plan includes 60 - 80 grams of protein per day.  My caloric totals are usually between 450 - 650.