Ranked (Bug?) Giving me a hard time

So im pretty new to ranked and trying to make my way out of bronze... Im trying to get out of bronze 4 and was on a win streak but i only gain 9-13 lp every win. Once i lose though, i lose tons... Last game i lost more then half my lp. I had 42 and that game i had 3 feeders then i lost 26 lp. Like why do i gain little and lose lots?