I don't really have this issue, but I'm used to the combat in this game. Didn't take me long when I started though, but it wasn't until lvl 50 until I started to realize I needed to git gud with my rotation since it was god awful. No doubt I made more than one group frustrated on my way to 50. But the general concept of XIV's combat simply clicked.

In WoW it's pretty much just button smashing in an effort to proc something else, but I'm able to transition from one to the other easily. Some people can, some people can't. It's definitely 2 very different types of combat. I'm sure with time you will be fine.