I lost about 47 pounds in the 8 months leading up to my surgery. It was the best thing I could have done. I lost about half of what I needed to lose pre-op.
We all lose at different rates so don't compare yourself to other people. Work hard to change your relationship with food. Use this time to change your diet to a sustainable way of eating healthy for the rest of your life. You need to be eating in a way that you can also maintain once you are at your goal weight. This will be different for everyone. Some people need to put some types of foods off the menu for good, or at the very least, for a very long time because they are triggers, some people don't.
Many people chose to eat low carb, some eat a more balanced diet. I would follow your doctors plan until you get to solid foods. You will have to evaluate what is going to work for you. I switched to a WFPB diet because I believe this is the healthiest for me long term. I think starting a regular exercise routine at 4-6 weeks post-op was the best thing I did for myself. I know losing weight is 80% diet and 20% exercise, but moving your body speeds your metabolism up, it improves your mood, it is good for your heart, and it burns fat and calories. It also gives you something to focus on when you get to the maintenance phase. You can shift your goals to fitness instead of weight.
Good luck on your journey.