when cycling a tank what you need is patience. i learned the hard way it took my 29 gal nearly 2 months to cycle. i made a lot of noobie mistakes though, rinsed my filter in tap water the first time, stupid stuff like that. just be patient you wont see any nitrates or nitrites for a while just the ammonia thats normal. also it sounds like is just a bad switch in your light, can you get to the wiring in that thing. if so an auto part store or hardware store sells killswitches and as long as you get one with the same amount of wires it shouldnt be too hard to install.