Don't freak out. There could be a host of reasons why you gained two pounds. Maybe your food's extra salty. Maybe you're under a lot of stress. Maybe it's almost time for the monthly visitor.
But do track EVERYTHING. Download MyFitnessPal or MyMacros+ or Baritastic and log LITERALLY EVERYTHING you put in your mouth BEFORE you put it in your mouth. Including water. Including coffee. Including the sugar and cream in your coffee. Including the oil you cook in. Including salad dressing.
Weigh things out—don't look at a piece of chicken and say well that's gotta be three ounces, get a $15 scale off Amazon or at Walmart and weigh it out. If you can't figure out how to track it, don't eat it. (You'll need to do this at some point after surgery anyway.)
Start "auditioning" protein shakes and protein waters. You'll be surprised how full they make you even pre-surgery, and most are 150-200 calories and give you anywhere from 20-40 g of protein. Start by substituting one meal with the protein shakes. Once you're past that, substitute another meal with a protein shake (add a little salad or something with just a spoonful of dressing if you're still hungry).
Drink a cup of water before you eat if you're prone to binging so your stomach's fuller.
You got this. It'll come off and your surgeon will say, yep, you're good to go.