Hi,
You are doing a really good thing by reaching out and asking about keys to success. You are going down a road that can be extremely rewarding, but it can also be frustrating.
Regardless of the root cause of your obesity, it is important to start working on creating a positive relationship with food. Counseling can be an important part of that for some people, and I highly recommend it. The better your relationship with food prior to surgery, the better you'll feel after surgery.
Start mimicking your life now for how things will be after surgery. Start eating very slowly. Chew each bit for 20 seconds. Drink at least 64oz or more of water each day. Ween off things like carbonated drinks, caffeinated drinks.
Start working with your doctor and physical therapist to create a movement plan and set goals for where you will be by surgery and what you'll do after surgery. Movement, such as walking is a major key to getting healthy and successful.
Don't get too extreme too fast. Do everything in moderation in a sustainable way. It's likely the pre-op diet will be one of, if not the hardest parts of your journey, but it is very, very important to stick with the pre-op diet for many reasons, not the least of which is to make the surgery safer and get you set up for success after surgery.
After surgery, stick to the recommended guidelines set by your doctor, dietician, and physical therapist.
Don't hesitate to reach out for help from your bariatric team. If something doesn't seem right, call them. If you aren't sure what you should be eating, call them.
Stay active on forums like this to connect with people who have gone through the ups and downs of this process. It can be very beneficial to read what others have gone through.
Be mentally prepared for pauses and stalls with your weight loss. It happens to everyone, sometimes within the first month, and it's often a cause of stress for people because they feel they should just be dropping weight all the time, but our bodies don't work that way. Weight loss isn't a linear process. It starts and stops, adjusts, and starts again. Sometimes that happens over a couple of days, and sometimes it can take months to see the scale move, but rest assure so many other positive things are happening in your body besides the scale moving, and you have to keep that in mind.
A stall isn't a failure. Every oz you lose is an awesome victory, and you should treat it and yourself positively on this journey. Don't worry about any past failures, and look only to the future. Stick to your plan and celebrate your choice of doing this for yourself.