I would fire the worst players you have, at least all the ones with salary <2000, and maybe a few more.
yes, and maybe you have also a good player (with salary over 3500) which you actually use rare or not at all in your games. You can sell him, he should fetch you some money to get a little while further. In the meantime your high level trainer will train up your other guys, so you will be able to sell off some players in the future as well to get new money in.
Unless you already are below 0 cash now, I won't panic yet...
They are not your friends; they dispise you. I am the only one you can count on. Trust me.