I picked up FF14 a few months back, I really got into the swing of it and felt like I was doing great, getting lots of commendations, no group wipes due to my own fault and feeling good generally.

But since lvl50 I seem barely able to maintain hate

In Leviathan I was off-tanking. I was doing my standard rotation for heavy swing, skull sunder, butchers block, with heavy swing maim storms eye/path to keep up the damage buff, and I was spamming overpower/flash regularly. I used provoke early on because it wasn't going on me, used a few overpowers and a flash, but as soon as I used my main combo it went to orange and I could not get it back again until provoke came back up.
I had to abandon the healers to the adds because whenever I tried leaving the tail to get the adds, not only could I not get the adds to orange with 3 overpowers, the tail would have dropped off me by this point and take a provoke to get back.

So for the love of god please tell me what's going wrong?