Do I even have a chance at getting into MIT?

You're about an average applicant, maybe a bit below average - you don't have a great shot. While you don't have to build a computer necessarily, MIT and other top schools are looking for people who have gone above and beyond what most students do in the fields they want to major in - things like building a computer, programming a game, doing original research, getting a patent - and you can bet a lot of the students you'll be competing against have done these things and more.