This last chapter is a pretty good example of relationship dynamics when one is young and inexperienced. Fear of committing to the wrong person, external factors trying to sabotage, misaligned libidos...
Yeah, when you've spent a lot of time and energy being confused about how to get in to a relationship, you're still utterly clueless about how, when, and why you'd get out of one. Barring some obvious incompatibility, abuse, deal-breaking behavior, etc., you question, "Is this the normal level of happiness/contentment that people have in relationships?" "Am I expecting too much, am I doing too little?" "Would I even have a chance at another relationship ever again?" "My partner is just trying to be nice, so why am I so annoyed?" and so on.
Hearing someone say, "It's not you--it's me" is horrible, but so is saying it and meaning it.