How can I improve my bed?

I am 6’5” 300 pounds and I have broken the last two beds that my landlord has given me. My current bed is a metal frame with a box spring with two queen sized top mattress. It feels comfortable but I don’t want to break another bed. Is their a unique way that I can try… sleeping on the floor is the next option right now if the beds do not work. Losing weight is not much of an option.