I can actually relate to Yotsubato not being super easy, though in my case it’s manga in general, I think. I find it way easier to read an actual book than a manga (even if it’s meant for little kids). I don’t actually know why, maybe because in manga you have to figure out the sometimes weird pictures, but I never seem to know what the characters are talking about.
You can always try to join the beginner book club. We are reading 時をかける少女, a fairly simple book that was also the first book I read, and I started at about your current WK level, so you probably can do it. Also, people post all sorts of questions about each chapter, which may help you too.
There are links to the discussion threads on the first post.
Check it out if you’re interested 