Wow, you certainly have made a lot of changes to your life all at one time! While I commend you on making those changes, I think it's important to remember that in doing so, you are having to re-train your brain through those changes...especially the one of quitting smoking.
It makes complete sense to me that you are feeling anxious right now. Making so many changes at one time is stressful (even when we know it's for our own good).
I also had my gall bladder removed a number of years ago, and to this day, I still have that pain in my back like I had before it was removed every once in awhile. I think it is fairly normal to feel that, but definitely get into your pcp if it will help ease your mind
Wishing you well!

sabby