Hit a rock, Prop not spinning- Also cannot get the bolts out of the lower unit

[Actonup32]

Here is the timeline of events:

-Bounced the engine off a rock going about 5 miles an hour in a river
-Motor revved without moving the boat for about 3 second before I shut the engine off
-Removed prop and it was not spun
-Replaceed prop
-Replaced flywheel key (the original key was not broken)
-Engine starts but prop does not spin
-When I turn the prop by hand the flywheel doesnt turn
-I can hear parts moving halfway up the leg
-I cannot get the bolts off to remove the lower unit

Its an electric shift 1972 Johnson 50hp

[Daviet]

Sounds like you might have broken a drive shaft.
Sometimes you have to use a little heat on stubborn bolts, mjust be careful not to melt anything.