Broken top.

As others have said - its impossible to give you good advice in this situation as we have little to no information as there's no diary or photos. If the plant is young (<2 weeks) you probably won't even notice the difference in yield as it's just like topping it - just do your best to let her recover as well as possible and don't stress her any more. If the plant is already in flower, then this will significantly effect your yield, but if you have lots of side branches, I'm sure you'll still get something worth smoking from it, so I wouldn't chuck her personally.

You probably don't want to hear this but yes. Start over. The amount of stress is going to be to much for the auto to recover from to produce anything significant. Unfortunately they don't have the resilience of photoperiod plants.

What creepy Steve said, depends on how old it is. Broke the top off a few times just redirects energy, if it's already in late flower wellllll. You might of lost some yield hope this helps

You've put us at a disadvantage by not having a diary.... have no idea how old the plant is for one thing! Is she in flower already? If so, just keep going.. if not, what you've done is to essentially top her and she may not recover - but it's still worth seeing if she WILL... I'd let her got a few more weeks and she how she does... and start a diary... please! Even if you can only reconstruct the past week, it will be better than nothing and we'll have more to go on when giving advice... Good luck....