Something is wrong with my computer screen?

My computer screen has had problems before but it's the first time it's ever done this. First for a while my screen would just turn off (go to sleep) for no apparent reason and the only way to get it to come back on was to power cycle it, but it would still cut back off within a few seconds. So I disconnected the VGA cord for a few seconds and plugged it back in, but now my screen has a greenish tint to it. I've looked for a degauss feature on the screen menu, tried to change color balances around and nothing works. HELP PLEASE!!! I don't have enough money to replace the screen and my computer is my only source of income! Any help or information will help