from personally experience, you just have to push through it. You and everyone else around you cant stop pause life just because you are feeling down. I know it can be VERY hard to find the motivation. Just have a good time today, go to sleep early, and wake up early tomorrow. When you wake up, DON'T STOP WORKING until you get it done, or its time to sleep. That what I had to do when i was feeling down. Hope that helps. Best of luck to you.
One of the first rules of depression is DO ANYTHING. Remind yourself that your brain is distracted by depression and that you still have control over what you do. Start with the simple things that make your environment more comfortable. Wash the dishes. Change the cat litter box. Put the dirty bath towels in the laundry and put out clean towels. Then reward yourself with something simple, like your favorite meal. While you do all these things, remind yourself that you can make your environment more comfortable and do good things for yourself.
Telling an unmotivated person to just "find motivation" is like telling a person who's continuously throwing up to just cut it out. What are you doing instead? Notice the types of thoughts you have when you try to get yourself to do your task, and talk to someone about them.
Know that it's OK to do nothing for a while, it might be just what you need. With that in mind, start out small, take a walk, surround yourself with nature, listen to it's sound. Don't become a victim. Surround yourself with positive people, have faith in yourself. And above all, know that God loves you and wants the very best for you. My mother had the best advise ever. She would always say,"this too shall pass." I've found they are important words for a lot of life's challenges.