What should I do with my life?

Go with what makes you happy. But I would strongly recommend that you finish school. No matter what you get your degree in (you can always switch majors to illustration or something like that), it always looks better to be a college graduate. I recently graduated with a degree in graphic design, but since I have a BFA I found out that I am qualified for almost any art-related job out there. And if you have a college degree, that puts you above the competition.

So to answer your question, yes, try to get an internship with a tattoo artist or something along those lines, but finish up your schooling too! Try to find a major that fits your lifestyle better, but stick with it, you only have two more years! If you drop out, it might not be bad right now, but I'm sure in a few years you'll kick yourself because of it. 2 years seems like a lot right now, but in the grand scheme of things, it's really not!

Also, switching your major to something like illustration would probably be even more beneficial for you. In my field, to get into the graphic design program I had to take a year of fine art courses. At first I thought it was a waste of time, but that year really helped me to fine tune my art skills. There are things that they teach you that you can't pick up on your own. Now, ofcourse I'm not saying that you can't be a successful artist without school, because you can, they just help by training your eyes to see things most people wouldn't notice, and by working on your individual skills and style. Just something to think about!

Why not do both?