Also...i think you should straighten your hair... eithe manual straightener(tool) or Japanese Hair Straightening treatment(a lot of money).
The hair on te back of your head is kind of thick, try getting it thinned or thin it yourself. to thin it yourself, you can use a razor or a thinning scissors. (this won't destroy your length but might cut it a tad bit shorter like 1-2cm at most approx.)
I wouldn't call it a J-Rock style just because it's messy.
As you can see by the two pictures posted, their hairstyles are very precise, clean, long and straight.