Major props for doing Occulus solo! I can't even imagine doing that, haha!!

Instances in regular mode aren't horrible, if you are having problems wiping just go out and level a bit and when you come back it'll be easier. Violet Hold wiped the floor with me at 75 as did Halls of Lightning, when I went back at 80 they were cake.

Heroics are TOUGH. Like a giant leap above regular instances. Stuff that I 1-shotted in regular have me wiping non stop in heroics. The good news is as you gear up it DOES get easier -- I wiped 15+ times on the first boss in Utgarde Keep heroic last week and gave up, this week after some quest/rep upgrades I went back and 1-2 shotted every boss.

Do focus on wearing tabards and getting reps up, it will help a lot.