Help me plz!

Hey guys I'm coming here to try and figure out what I'm too dumb to do on my own. I'm having a rough time climbing In ranked atm and I can't for the life of me figure out why. I do really well, most of the time I usually win my lane hard. Most of my games I'm almost always positive k/d sometimes I'm double digits in kills. I'm not toxic and I try to work with my team best I can. Sadly I still lose. I must be doing something wrong right?

I also play smite and heroes of the storm and I completely decimate those games. If my team is doing poorly I can most of the time push through and still win, but in league this seems to be way harder for me.

Plz guys help me out! I really love this game and want to continue playing it, but I feel like I'm going nowhere fast