Sentence:  But it's even harder for me, because… I am a <WSD>completist</WSD>. Once I start reading an author's work, I need to read everything that writer has written. I can't veer away. I need to check all that author's books off my mental list. My knowledge of their work must be complete. 
Meaning of the word marked with <WSD> tags:  A collector who strives to obtain a complete collection of some type of thing.