MY NIKON D3100 ISN'T WORKING! QUICKLY

We have this activities week at school this week and tomorrow (Friday) we have this photography day, I knew that we had this so I put the battery from my dslr (nikon d3100) in charge from sunday. A blinking light indicates that it's charging and a sold light indicates that it's done charging. Well, today (thursday) I went to check on it and it still has a blinking light! I thought that it would be charged (but not fully) but it would still work so I took it out, put it into my camera and when I tried to turn my camera on it wouldn't turn on! Just nothing! It was working fine before I put the batteyr in charge and even when I charged it before it still worked but now it doesn't and I need it for tomorrow! I've only had this camera for around a year and it's annoying because I saved up pocket money to buy it and now I can't even use it anymore or even use it for tomorrow!

Please help.

Added (1). To Photofox~ The charger indicated that it was still charging and so it hadn't finished charging… So that's why I didn't take it out I thought that it would eventually fully charge

You left the battery charging from Sunday to Thursday! You should remove it from the charger as soon as it's done, not leave it all that time. You might have damaged the battery.

The charger may already be damaged which in turn damaged your battery. Recharging usually doesn't go beyond eight hours for most applications. If it doesn't fully recharge overnight, there's something wrong with the charger, battery or both already. You shouldn't be counting days.

There's no other solution. Buy original replacements.