Stupid bike

So my bike is pretty lame and especially the bicycle chain. I don;t have a back light anymore, it got stolen, one of the brakes is broken, the gears are not working anymore so I'm stuck in one position and all this would be doable if that damned chain wouldn't run off the effing whole time. In what should be a ten minute ride home it ran off at least a dozen times. Cursing, screaming and tantrums followed after...I guess I should buy a new one because fixing this bike probably costs me the same or more as a new/second hand one.