Ignition cylinder will not turn to the off position?

Yep, the ignition key and tumbler need to be replaced. here is the instruction in the diagrams below click to enlarge so you can see how to do the job. You may be able to spray some WD40 into the keyhole, this might loosen things up and get it to work again but if not, replacement is required. This guide can help:

https://www.2carpros.com/articles/ignition-switch-wont-turn-stuck

Check out the diagrams (below). Please let us know what happens.