Don't take this the wrong way but it sounds as if you are just as inept as your fellow raiders. 3 hours of dieing and you couldn't pinpoint what went wrong on each attempt in order to improve it? You should stick with that guild tbh and grow with them. If you join an even half competant guild they'll drop you for not having a clue.
You're probably right, I'm not afraid to admit that I sometimes don't bother reading the tactics of bosses. If a guild feels that I'm too "inept" and kicks me, I just have to accept that. Can be avoided by learning the bosses properly ofcourse. You don't learn anything properly in a raid where noone understands whats going on though.