I made it clear from the beginning that I'm not interested in a friends-with-benefits arrangement.Do you think I'm overreacting or is he trying to take advantage of me?I like to imagine my life without Bill Murray (that's the cat's name, which is such a waste of a great name on a terrible animal).
In your question you asked if you were overreacting.
Maybe not marriage, but are you two even talking about moving in together? A fact I'm deducing from the fact that she is a girl and it is a cat.
Don't make her choose, because you may not like the answer.
More than wanting to be friends with benefits, it sounds like this guy might just be done.
There could be a million reasons as to why he's distant: busy at work, family problems, just started that part of the hero's journey where he has to go underground, etc.