Hi Liz,
We are sorry you have such difficulty. Please try to navigate to Sync Calendar Status at the top admin bar. Then try to Abort the process and Delete all the logs of imported bookings.
We do not recommend keeping the old logs in the database so you may navigate to AccommODation Settings and scroll to the bottom of the General Tab to switch automatic removal of the logs that are older than 1 Day.
best regards,
J. Davis