Hi Jenny,
Well, congratulate yourself for spending seven years with each other! It is not a failure, even though it did fail ~ seven years with anyone or doing anything is considered a triumph in my book and nothing to sneeze at.
Now, as to the boyfriend: He went from a cute sweet boy to a mean ass in a man’s body. You can theoretically chalk it up to the new Quarter-Life Crisis phenomenon. But you definitely have to let him go. Forget marriage, and owning property with him.
Break up with him and revisit him in a year (if you’d actually want to). In this next year go hiking, have girls night outs, get makeovers, meet grown-ups, find a new place to live if living with him, etc.
You know what to do. And especially what not to do. No deep talks necessary. He doesn’t deserve them. Tell him you’re taking “a break”. After a month or two of no contact he will realize you dumped him.