Battery won’t charge/now won’t turn on

Hi,

I have a MacBook Pro late 2011 edition. I was working on my computer when it randomly shut off and when I turned it back on it had an X in the battery icon and the charger light wasn’t turning on. It had been charging all night. I was able to use my computer and tried trouble shooting with turning it off/on and then tried control/option/shift/power all at the same time and it wouldn’t resolve. Now the battery has died and won’t turn on. I have made an appointment to have it looked at. But in the meantime is there anything else I can try? Or will it be able to be fixed or the battery fixed if it won’t turn on? Will I be able to recover my files? 

Any help is appreciated because EVERYTHING is on this laptop and I made a rookie mistake and haven’t backed it up. Please help:///