Ok breathe. You haven’t messed up.
First, because a lot of nerve endings have been cut during your surgery you won’t feel full like you used to until you’re healed. Now you’re on soft food you’ll likely start to feel full sooner as soft food takes longer to pass through your tummy than liquids & purées. But try to avoid feeling full. (You don’t want to stress or put strain on your healing tummy - remember all those stitches & staples holding your tummy together.) Because it takes time for the message to get from your tummy to your head, by the time you think you’re full you’ve likely past full. Make sure you eat slowly to allow time for the message to get through. Asking myself if I needed the next bite or just wanted it was a game changer for me. I still ask myself that question.
Second, portion size is very important. What portion size were you advised? Mine was 1/4 - 1/3cup.
Thirdly, our weight always fluctuates. Fluid retention, constipation, eating a little more one day, etc. can cause us to gain. Plus, there are stalls. Many experience the first one at about 3 weeks - can be earlier can be later. They tend to last 1 - 3 weeks. You can experience a couple of them as you lose. Your body is going through a lot of changes & it just needs a break to come to terms with everything. They do break. Just stick to your plan.