Sorry to hear about your situation. You can cut your loses not and sell at a loss or let it continue to bleed you of money each month. For insurance try getting a cash value policy as it will be most likely cheaper than your replacement cost policy. I just did this and cut my insurance bills in half. By the way here in NY where my properties are I pay about 140$ a year to insure them.
I would look for a new manger if it has been empty that long. Have they given you any feedback as to why it wont rent? There must be something your not seeing, they are not advertising, house is in disrepair, or maybe rent is to high?
If it was me I would get a new manager who is aggressive (or seems to be) in getting it rented. If things still dont get better I would cut my losses and dump it. At least then I would not have to worry about what the next major repair will be and what it will cost me. It was just an expensive learning lesson but everyone on here most likely had one before. good luck