This is very similar to my life. I took Engineering because my parents' decision though I was very interested in joining Fine Arts. A lot of people including friends, relatives and professors tried to talk my parents into agreeing. But they were firm. I went off to do engineering and even higher studies in Biomedical engg. Wen I returned, I was idle for a very long time. I knew at that point, when I had someone to support (my mom retired when I returned from melbourne), I decided to work. I didn't start big, I didn't get into IT like the other girls around me. I joined a small firm as a content writer and grew up from there. Today, it's enough money.
When I got married and sunk into the married life, I realized that my life turned monotonous, boring and lonely.
I got back to doing what I love... Painting. I am no professional. But I have enough passion to experiment it all ways. And that's what I am doing now. "smb" is right when he says not to make a living out of art for now. Keep it for your spare time. Share your paintings with friends or gift it to them. This way you'll gain some popularity and motivation. People will give you ideas on how to improve, what you can try and suggest you what they did. This way, you can also identify your area of expertize and become unique. Save up all your art and have an open day sorts, an exhibition maybe.
If you have a family to support, then it would only be wise to keep a regular job. This is all my opinion.
Cheers,
Ashika
http://ashikaprabakar.tumblr.com