1st Congratulations on making this decision for yourself, it's not easy and takes a lot of mental strength, so good for you.
This happened to me. WALK ALOT and make sure you crush all pills and vitamins until you reach week 4 or 5 post-op. LOTS of water, drink it SLOW. Drinking water too fast trapped gas for me and I had to walk to get it out, it was not pleasant.
The pain is real! I was 2 seconds away from going to the ER myself. As you move into the pureed food stage, same thing eat slow, cuz if you think the gas hurts in the liquid stage imagine gas stuck with a soft food in your new little stomach.
Anyways...You got this!