what if everyone woke up tomorrow and it was 1993 again? Assume you retain your 2013 age. Bill Clinton is newly President, the Internet (insofar as there is one) is a toy for university science departments, and the most cutting-edge games available are SimCity 2000 and Doom.
Go.
Honestly? I would drop everything, and immediately track down a theoretical physicist at a university, and explain to them what happened. If I didn't have any futuristic doodads on me (cellphone, GPS, solar watch, or whatever), I'd prove myself by talking about all the cool and entirely plausible inventions that are commonplace these days and the mechanics behind which they work... and if that's not enough, I'll start predicting events that will happen, songs that will be written, etc. Once I've got them convinced, I'll do my best to help them understand what happened to allow me to go back in time, so that some day, the event can be recreated and controlled.
In the meantime, I'd try to capitalize on my fame as "That guy who came back from the future"... build a name for myself until I show up on talk-shows, chat about how amazing things will be, maybe warning everyone to help avoid a crisis or two, that sort of thing. I have to imagine most folks will be skeptical, but at minimum I'd like to try to give folks hope for a bright future.
At some point, I'd have changed the timeline in innumerable little ways which will probably make for a different future, so my predictive powers will become less and less accurate. Through all this, I'd avoid letting anyone know my actual identity, so I don't mess up my past-self, and don't get him singled out by folks who think they can kill kid-me and mess with causality. I might try to help my family out still, approaching them as my dad's long-lost biological kid-brother or something, work to help them make ends meet so the stress doesn't drive them to some of the bad things that happened later on. That sort of thing.