They have a digital scale at wal-mart that will let you weight your food on a plate or whatever. I think that is my favorite go to tool. This scale and my 8oz grab and go dishes.
You will be fine... I am 21 days post-op and I had the same thing... Try taking smaller sips and not swallowing air I had to learn to let whatever I drank hit the back of my throat before swallowing which made the burping so much better. Congrats and good luck!
I had my sleeve 3 weeks ago... My husband also had the sleeve but his was 3 months ago. I have lost 23 lbs. And he has lost 86 lbs. I can defiantly say 99 lbs between the two of us has mad a HUGE difference in "O's" and I just came off restrictions