Is anything that can be done about my shrinking belly button? (photos)

Thank you for your pictures. There's really nothing that can be done now about your shrinking belly button. It needs to heal and become stable. Once it stable in size then potentially and umbilicoplasty can be done. This is where the bellybutton can be open up a little bit to look more natural. This is a surgical procedure.

Try inserting a small marble and increasing the size by stretching.Best to discuss wit for surgeon... 

Your surgeon should be able to fix it. Injection will soften the scar but will not make the opening bigger

Yes, there is a nonsurgical treatment for an umbilical contracture. Go find foam ear plugs at a local shooting range and lubricate one with some nNeosporin. Work it into your belly button and leave it there all day. You can remove it to shower. The gentle expansile pressure of the foam will stretch the scar. Do this for at least a month. Usually works and it's painless!Good luck!