I thought the same thing, OP. Then I decided I wouldn't let it get to me and did some real research. First, I checked out some guides. The problem with using a healing guide is that healing isn't like DPS. It's situational. However, with some trial and error, I really turned everything around as a Resto Druid.
First, don't be afraid to use a cooldown. Ironbark is amazing, and I tend to drop it on my tank during big trash pulls at the start. This helps a lot. Our Mastery makes each heal stronger per HoT we have active on the target. I love germination for this. Soul of the Forest is great with Wild Growth to really heal up the group. The first tier talent is something that can be hard to decide on. Extra Swiftmends means more procs of Soul of the Forest. However, I am actually enjoying the fast cast on Healing Touch now that I have some good stuff unlocked on my Artifact.
The biggest thing to remember is that Resto Druids are all about preperation. Because we HoT more than anything, we have to start building our party up even when damage may not be going out too hard yet. Know what's about to happen, and prepare the group for it.
I hope this helps. I love healing as Resto, and have been enjoying Mythics!