Wow, something's definitely not right. Did you do it yourself? I installed Eibachs myself and it went very smooth. Are the springs sitting in the perches correctly? Did you bolt the upper mounts back in the same way they came out?
Did you drive the car around a little to let it settle? I went through OCD hell lowering my C6. All 4 corners are ride height adjustable in those cars. I must have measured-adjusted-remeasured at least 100 times before I was happy with it lol.