Photos would help. How falling apart.
Hi T, maybe this video will help out - https://www.youtube.com/watch?v=oYyNCEyStYQ As William mentioned a photo will help us give you the right advice
Glue them back together and strap them with ratchet straps while they dry.
Take them out and try to reinstate the bottom board into the ridges on the sides. For stability I would also add some support across the bottom of the drawer too, and try not to overload again.........
Glue them with carpenter's glue starting with re-inserting the bottom of the drawer into the side slots. Then use rachet straps or belts to keep them together and squared. Wipe excess glue off with damp sponge. Let dry overnight.