Obviously, everyone has their parents and family who "supports" them, it is their job (but they do love you even when it seems like they don't. Even if you are not super super close with your family there is at least one family member who has your back. Mine is my mom. She is my best friend even if we are 400 miles and six hours apart right now. I still have her, ALWAYS.
But support systems are more than just your family or your mom. You could be in high school or college or even in the "real" working world and you still have a little army of support behind you (whether you know it or not). In college, you have your friends who really are your family away from home.
No matter what is going on they have your back.
Recently I had a mild quarter-life crisis and had no clue what exactly I was going to do with my life but I was able to just talk to the people I live with and my friends and they gave me input and helped me weigh out the good and bad. I did not even have to ask for their help, it is just natural to do it. And the thing is at the University of Maine, you don't even have to be friends to get support from the people around you.
No one wants anything bad to happen to anyone here, we are a huge black bear family. You might be having a bad day and literally, anyone will sit and listen and try to make it better. Whether that be your roommate, an RA, a neighbor or just someone in the library. Someone will notice you're upset and try to help.
Recently I had a big interview for a graduate school and had to missed class. It was a small class of eight of us and one of my classmates was presenting. I had talked to the professor about missing and he was aware but did not tell anyone else in the class. Later that night I got a message on Facebook from the presenting classmate congratulating me on the interview and asking how it went.
I had support, from someone I hardly knew.
But having a support system is everything.
It is not just important in high school or college or the real world. If you have to have a major surgery or procedure a lot of the time they will not allow you have the surgery or leave if you do not have a support system to help you through the recovery. Having someone there to help you will make everything easier and just more bearable.
Remember that if you feel like you're alone and have no one, to take a step back and look around you. You probably have more people than you think.