Hi,
You will need to do some corrections and then start to do frequent bg tests after the low, and then using the results, you can start to alter the basal rates. This will be very trial and error though so may take you a few nights to get things ok again..
Dont know whether you feel confident to do this yourself but if not, get in touch with your hospital dsn as they may be able to alter them for you.
Everyone with a pump has to go through all this so try not to worry.............