Can you switch doctors?? If not, your mom's got it right, you do you!
I'll preface my experience with: I got my gastric sleeve in Mexico, no insurance/approval hoops to jump through.
My doctor was cautiously on board with me having bariatric surgery, but was wary about the Mexico part. He gave me all kinds of horror stories, personal "aftermath" ones that had shown up at his office after assorted procedures abroad. Then he thought about it...said at least Tijuana was super-close to the US, and all of the horror stories (abcesses, drain infections, etc) were from getting plastics overseas. He wished me luck, and today he took out my stitches. He was impressed with how neat, clean, and minimally invasive the work was and said he looked forward to seeing me for my post-op blood workup.