Please tell me if there are any alternatives that don't involve braces to fix shifting teeth?

Invisalign: Invisalign is a system that uses plastic aligners to move teeth without braces. Search for it on the internet.

Shifting teeth: Usually means you have lost bone support. You probably need a periodontist, an orthodontist, and a restorative dentist working as a team to resolve your problem. You have a serious problem. Resolution of your problem requires quality care, not short cuts. Seek competence.