asma2712
I know how you feel. I went through a similar situation before I was diagnosed with severe major depression. My mind would race, but without any thoughts, I couldn't think, I couldn't sleep, I couldn't eat. It was an indescribable pain. Like you, I was able to fake my way for a while, but then the dam burst.
I don't want to sound rude, but your mother's statement is inappropriate. Yes, this world is only temporary, but there are so many things in it to live for. If there weren't, you wouldn't be going to college, you wouldn't have friends and you wouldn't love your family. Your life can be what you want it to be - it's an open plan just waiting for you to fill in the blanks. Think of the things you are passionate about, those things that make/made you happy. Below is one of my favorite quotes by Paulo Coelho from The Alchemist. It's something I think about when I start falling.

"Its about the faith, power, and the courage we all have within us to pursue a path charted by the mysterious magnet of destiny but obscured by distractions. We learn to trust our hearts, read the seemingly inconspicuous signs, and understand that as we look to fulfill a dream, it looks to find us just the same... if we let it."

Don't give up. Your life is waiting for you.

My suggestion is that you see the school counselor. That person should be able to help you get back on track or refer you to someone who can.