Dressage for an ex-hunter/jumper?

I've been riding English since i was 10 stopped when i was 12 (due to financial reasons) then picked back up ridding just this past summer (i am 17 now). And horses is just in my blood. When i wasn't able to ride i was on the local FFA horse judging. Since i was young I've ridden hunter/jumpers often traveling to different barns and stables learning from different instructors(i guess you can say i am a drifter lol) but now that I've found the perfect barn and i want to take my riding education seriously now that i am about to graduate high school i am starting to learn dressage but i cant seem to get the gist of it. Has this happened to any of you ex- hunter/jumpers? if so do y'all have any tips? i want to do cross country/eventing and realize that i must learn dressage to compete