house insurance question?

i have house insurance it was really cheap but this month they sent me a bill for 3 times as much as i was paying, well after hurricane katrina damaged our property they cut us a check but it was for only 3 thousand dollars they charge more than that to redo the roofs so we havent gotten all the work done and we basically used the money for other repairs to the house repainting, flooring things like that. my question is what will happen if i dont pay the insurance and they cancel it. will i just not have house insurance or will i be held to pay them somtheing because they paid us a check for 3,000 dollars my husband isnt working im paying all the bills and i just dont have the funds to squeeze this other bill into it. need some advice from someone who knows about this thanks.