I've read HOH I and reread the parts that i've struggled with/didn't understand.

Well, I feel I'm pretty solid in most of the concepts (my discipline can be lacking at points) but the middle to late stages of the games are where I always struggle, I've made it deep ITM one placing 15th in out of 920ish in a tournament last week, but have never made a final table, and if/when I usually make the ITM, it's the really shortly after i'm ITM i drop like a fly. So would HOHII be a good investment?