Someone ("famous") stole my idea!!! Help?

Okay, I'm a sopre in college (UGA) and I created this cartoon/ comic strip back in 10th/ 11th grade, and now there is this person who is coming out with a cartoon series of the exact name and nature. I unfortunately didn't have it trademarked because I was taught anything about copyrights/ trademarks etc (1st generation college student). Is there anything I can do, because I did plan on making this cartoon/ strip myself. I am also almost 100% sure this person stole my idea because we come from the same area, and I used to show them to everybody in my cles. My earliest concrete proof would be the copies I sent to colleges in my applications. This sucks so bad. I had a theme song and everything.