What does your insurance contract say? Are you entitled to receive money for the loss of income? If so, are you entitled to receive the full amount? How is the amount for loss of income calculated in the insurance contract? Did you talk to the insurance adjuster? What was the insurance company's explanation of why they sent you less amount than what you claimed?
If the loss of income cannot be claimed fully through insurance, are you able to recover from another entity e.g. the owner of the building? What caused the floods, who was responsible?
All of the above questions are relevant and will help you determine the answer to your question.