publications - What to do when research leads to poor results?

I am an MSc graduate and work as an independent researcher. I spent 10 months on a paper. I wrote many scripts in Matlab to implement four other comparative methods as well as a new method that my MSc professor had proposed. Each of these methods was so difficult to implement.

Unfortunately, the method that I was going to propose does not work well compared to the comparative methods, which were introduced already 3-4 years ago.

What should I do now?