I won't lie, leveling AST felt a lot more difficult than leveling WHM for me. I always kinda felt I had to heal more with AST. However, I know about the job in paper, and I think it has some of the best healing tools in the game, even moreso than Scholar. The only reason I haven't leveled AST to 60 is because I don't really have much time to play lately, and I just really, really love how Scholar plays. Being a fan of solo healing things, though, I think AST has the coolest tools for the job.

My advice is to not be discouraged! AST has received TONS of buffs with every patch. To the point that I think they might have overdone it a bit, haha, so I think the information you have about its potencies, etc was either misinformed or just plain outdated. It always takes a while to learn how to play a class properly, and Astrologian is a very complex job because on top of healing you have to do card micromanaging. I bet you'll get better at it eventually.