Have I lost it with Xerath or is he unplayable right now even against Mages?

I used to be really good with Xerath, I used to beat Zeds even in S3, before and after the rework.

But this season it's like I can't win a single match with him. And I don't seem to be doing really bad "baseline", it's just that other ppl seem able to dive me and get the kill just because I can't retailate even if I stun them. After that I get the usual 1vs2 in lane, I also noticed that my farm has deteriorated a lot.

I didn't lose the habit of warding everywhere I can though I noticed that it has become a lot more dangerous. I trield Thunderlord's in order to get some help in my E-Q-W burst combo but that usually resulted in a not optimal teamfights phase, I tried Deathfire Touch but then my in-lane damage is so low that I might aswell be without a Keystone, it seems even Xerath range has lost it's advantage because the difference between it and the easiness that other mages get to get in and out while bursting you for a ton of damage is ina favor of the enemy.

I don't know, this might be just my feeling. Feedback appreciated.