Suburban water heater problem

I fried my heating element when I plugged my TT in to get ready for this season and the water heater was left on from last season. I installed a new element and tested it out. Got hot water.... woohoo! Then went to turn it off and the rocker switch on the water heater wouldn't go to the off position. Went in the rv to flip the breaker and noticed it was tripped. Flipped it back on, went out and was able to turn it off with the switch. Tried again and again the switch wouldn't turn off but this time no tripped breaker. Flipped breaker and then could turn off the switch. Not feeling very confident, I went out a few hours later and the water was still really hot. Its like its not shutting off. Unplugged the rv for tonight.

Any idea what I obviously did wrong?