The two most difficult and critical revolver smith jobs are replacing a barrel and fitting a new cylinder.

Both require the services of a Master pistolsmith who also has the expensive tooling needed.

Cylinders are not "right" just because you can get it to snap into the frame.
Buying a replacement cylinder and expecting it to just fit correctly is unlikely.

Search for replacement cylinders on ebay, Gunbroker.com, and by placing Wanted ads on the gun forum Classified sections.

If you find a good usable cylinder, be smart, unless you're a qualified pistolsmith send it to someone like Frank Glenn in Arizona.

Frank Glenn-Glenn Custom Complete Gunsmithing Service Glendale AZ

A major danger of a cracked forcing cone, in addition to the further damage to the frame as above, often a cone section will break off, spitting a large chunk of shrapnel into yourself or an unfortunate bystander.

REPLACE THE BARREL, and STOP SHOOTING IT until you do.