Advice on a matchup I should have won

My opponent picked Singed, so I picked Kayle, which is a known counter to Singed. I don't have a lot of games with Kayle but I don't think I am all that bad with her (I got a penta in a 2v5 and then ended the game :D). Anyways, I am against Singed and at first I am doing fine, I am farming with relative safety (pantheon was top and mid a lot and it was hard to push out far.), but then something bad starts happening. He hits me with his slow and I can't out run him anymore even with my Q and W he still flings me. Once he flings me I run past him and take about 60% of my HP just from that one fling.

He has ghost and with his ult, I can never escape him nor chase him, plus he does a shit ton of damage and I don't seem to hurt him at all. Like no matter what I did he out damaged me and out pushed, plus Pantheon diving me, i lost really really badly.

So what do i do against that singed damage and his ability to chase me down at sonic speeds?