That sounds pretty cool, wish my high school offered that (the most advanced we had was AP calculus AB). If there aren't any more math classes offered at your school after you finish DE's you should take a beginning linear algebra course at a local college. You'd probably like it, it's different than calculus but it's right about the same level as DE's in terms of rigor.
Yeah, that's all there is.
I'm not sure what I'm going to do senior year, at our school we have this "young scholars" program which is a partnership with UMD, and I'm going to take a social psychology class second semester. I'll also probably take AP physics, and I need a tech and english class, plus band, so I don't know what else I'm going to do.