Piece to HALT a flow?

I want to be able to add in some error control. (I ran into an odd issue where a flow was returning the wrong row from a Google Sheet, which is what led me down this path.) I wanted to build in an error control step to basically check:

Router: Is all of our data correct and expected at this point in the flow?
Branch 1: Yes → Proceed with flow.
Branch 2: No → Notify me and STOP the flow.

But, I can’t figure out a way to stop the flow. I could have if I had thought to add this router into the original flow when I was building it. But, I was trying to add it into an existing flow, so I get this:

It would be great if there was an Exit flow piece that I could add in that would allow me to exit the flow, setting the status to failed/success. But I’m open to some other way of doing this if you have an idea!

Facing the same issue here where I need a circuit breaker to stop a flow from executing more than once at a time. Did you find a way to do this via code or some other method?