Neck Strength and Rehab

I would like to know if anyone has any bridging alternatives to build neck strength. I can touch my nose doing the bridge, but I cant move my neck for several days afterward. So, I need some alternatives. Any help would be appreciated.

Does anybody have any suggestions?

some guys hang weights from their heads… don’t know how efficacious it is… I know Boxers do something, because poor neck strength = easy KO, but not sure what they do.

Manual resistance. Either do it to yourself or have a partner do it. I believe Iron Mind sells a head harness thingy for neck work as well, but manual resistance is cheap (free), nearly infinitely adjustable in terms or resistance, ergonomically sound, and effective.