Q: "What do I do when nobody believes I can do anything with my art."
I'm sorry to hear that, it's really tough when the people close to you don't seem to support what you want to do. I'm sure they care about you, but would rather you focus of getting a career in a more conventional and 'safe' job.
The truth is that you will have to try and stop being around them or at least stop talking about your aspirations about being an artist when you are with them.
Drawing and drawing education is huge right now and so I've sourced a few examples of people who are able to make a living from their illustration through commissions and education.
Maru is a comic style illustrator who is doing a course on how to draw comic book characters. She has big plans and so I thought you might find it inspiring. If you sign up for her newsletter you get a PDF guide on how to draw characters.
Snapchat influencer artists.
This guy: http://mplatco.com and this girl: http://cyreneq.com are killing it by using their drawing / illustration style over snapchat pics.
She also set up: http://www.the11thsecond.com to help brands find people on Snapchat.
They are both good on camera and can draw. Although their style is perhaps a little generic in a conventional sense, it hasn’t stopped them becoming hugely successful.
On a ‘teacher’ note: have a watch the video below until 6:20.
Online education is a huge opportunity for you in my opinion, but don’t listen to me if you don’t agree, you have to do what you love.