Although I am an absolute noob at this subject, it sound very much like you've taken too much to me. As I said, I've only had a little dabble myself, but from what I gather there isn't a great deal to feel, as such - it's a rather subtle thing, so not one to go for if you're looking for massive speedy rushes.
EDIT - Too slow again 8). Listen to SHM - he knows a lot more about it than I do.