A bit late but... If you have a losing spree just stop playing league for the day. Just go for a walk or go play a game that relax you or something that will make you happy. Than go back in good mood. Other thing is just to play more and read/watch guides. There is the Practice tool right now so you can really put it in use to improve your item builds or combos(or to find a bug ;P). Plus that you need to ask fro help in-game if someone is main the role that you play right now, if he is main of the champion that you play right now.
I can't anything eles becouse of the information that i have right now. If you need more help don't be afraid to ask me.
Best of luck on the fields of justice