Can't get as many kills as I would like

So recently I have been having issues getting player kills before hand I used to be able to push lanes and get tons of kills, but now I am usually lucky if I can defend tower and when I do have someone on the ropes they somehow kill me, which in affect gets them fed and me having to struggle more. The characters I usually play as are mages (Zeus, Ao Kuang, Freya, Hel to be more specific). My kills started to decline when I hit level 18 and ever since then I suck :( I don't get it why is this happening? If anyone can get me some feed back it would be most appreciated.

This is probably because you are lvl 18 which means that you are playing with a bit more higher lvl than you are used to, just keep playing safe until you are comfortable enough to get loads of kills.

I had the same problem when I reached level 25. I did exactly what Muas said to do and after a little while was back to doing fairly well again.

So, midlane, I presume?

just farm the lane, and hug your tower, and poke the opposing laner. When you think they're low enough, go HAM. A good way to learn how to play like this is to play a lot of Zhong Kui - that's really the only way to play him.