I felt the exact same way. I think it is completely normal. I started to question my decision and what if's. I also freaked out because this is a permanent decision and starting worrying about the potential side effects.
I'm so happy with my decision, my only regret is not doing it sooner. I'm 4 weeks post op and I'm down 30 lbs. I feel great. I have been quick to adapt to the new lifestyle. It is not as hard as you would think.
My main struggle was nausea but it passed. I also did too much too soon and set my recovery back a little.
It is worth it. Stay positive and you will love your results.