Welcome to the forum, Al, and I'm sorry that you've had a bad day.
Most likely the connection between the chain and the cables broke, but it could also be cable skipping off the rudder
quadrant or some other pretty simple failure.
In any case, you can repair it. It's simple. Dig in and find the problem. If you need new chain or chain fittings, go here:
Get to know the McMaster-Carr catalog; it's very easy to use because it's a branching system that leads you through narrowing down to what you need. Measure the chain and look on the sides of the links; "45" means it's a group 45 chain in the catalog. You can do the same for cable fittings.
It only gets rough if you (very unlikely) have a damaged rudder quadrant. You might have to go to Hamilton Marine
(they support commercial fishing
boats) for a new one.
Hang i there, and let us know how you did with your first repair project