I agree with most replies that you should not be expected to cope with frequent (any) changes of instructor, specially in the early stages. It's all about confidence and it's easy to see that yours has been damaged. Confidence in the instructor is key.
You don't say what period your 8 hours were completed over? Try to have one lesson a week, minimum, better 2 per week. This may mean booking four a week, due weather and other factors...