Hey welcome! You hit your first stall, yay! Now you can get it over with. I read so many posts here about stalls and they were so, so helpful for getting me through. Let me try to help you out!
It is totally normal, in fact, expected that you'll hit a weight loss stall sometime between 3 - 6 weeks after surgery. I am 4 weeks post op and I just came out of my first stall that lasted 1 week. Your body is adjusting to the new normal, your fluids are all out of whack and your body is freaking out. As you slowly increase your protein and calories, your stall will break on it's own. However, your body is still getting smaller. You are losing fat which you can measure on a body composition scale. (well priced around $35 on Amazon)
Your clothes are about to be looser, you're going to have more energy and all kinds on non-scale victories are going to crop up for you. Enjoy those while the scale is acting like a turd. You've got this!