I need your help high elo gods :)

Hi,

Im currently at gold5 and i can literally only play kindred properly. Im at 340k mastery points and ive started to get bored of him. I could also play anivia pretty well with 120k mastery but shes useless after those nerfs.. I tried to play other champs but i ALWAYS feed to the point i could end the world hunger. It doesnt matter what i play, if its not kindred my skill level will be bronze1-. Ive tried practicing other champions, i have level 5 on many but i always feed. I play them on normals, i carry. i go on ranked, i feed hard. I really need advice i cant understand whats wrong. keep in mind im new to the game i started at the begin of season 6.

Thanks.