Well, routers die all the time. In fact, you can bet your router is going to die in a few years, and given that you've been using it for a few years now, it's due. Weird things happen when routers start to die... software connection aborts are the most common, but other things can happen too.
As you said, it's been broken ever since you got back. Clearly something changed, so you can pretty much ignore the fact that it's been working for years and assume anything can be at fault.
