Hi honey! Get lots of rest but do try to get in some walking...it helps with the the pain and prevents bloodclots.
I'm like you...I need to know where my limits are....talk to your NUT if you have any questions but here's what mine said.
I was told for the first week, it's Protein Shakes, 1 oz 3 times a day and 1 oz of something protein inbetween each meal. I ate something every 2-3 hours or so. In between...sip sip sip the water. Try freezing a water bottle and sipping the melt off when it gets to be about an oz.
Now for food, I couldn't stomach eggs in any form so be careful of that. Cottage cheese (small curd in very small bites [I used a baby spoon!] and chew it 40 times each bite...make it liquid before you swallow), Chicken stock with salt (I needed the salt content. I had an issue with not enough salt for a few months after surgery. Bullion if I didn't have the stock...but stock has protein...better for the cause! hehe), a very thin pruee of lentals or beans with stock, SF yogurt as long as it didn't have Fruit pieces in it, etc
Good luck and come here often!