Frankly, the answers you received show no understanding of your problem. They are fine for consumer debt, but your issue is business debt.
I don't know where you are that a 15% interest rate is reasonable for this situation...but let's assume it is.
You have a few possible solutions:
First, find a partner who believes in you and your business and can invest through equity rather than debt. This will reduce your monthly costs
Secondly, approach your lender(s) to renegotiate a longer term loan with lower payments. I don't know what your security was against the loans, but if it was the business assets the lenders would prefer repayment rather than taking over your business and maybe getting pennies on their debt.
Reduce the loans through assets sales, as you have suggested.
Whatever path you take, get a good advisor to work with you, as you might be blinded by bring in the business. They can bring an outsider's eye to your problem.
Good luck in your future!