Nah don’t give up. I’ve snapped the same plant in half about three times now. One time I took the branch I snapped off and turned it into clones. I’ve got four happy little clones now.
I was with @Underthestairs until you said auto. You will now have two mains to LST. This is a rhetorical question, will this early stress tend to increase veg time (in my book that is not a bad thing) which will lead to a more productive plant? lets hope so. Some auto abusers would say top those two mains again. I would say be good with two mains and baby them for a couple of weeks with gentle LST done to separate the mains into a Y.
This happens so often maybe it should have its own acronym like FIM. How about FULST. F*cked-Up- LST
Good luck