You have created a skate board
Have you fitted lowering springs onto the existing shock absorbers?
Are the existing shock absorbers in good working order?
Do the existing shock absorbers have adjustable bump and rebound?
You are experiencing bump steer I guess? Hence the skateboard comment.
Does the suspension have bump stops and how far is the suspension off the bump stops when the car is sat still?
Do you feel that it wanders left and right for no reason on a straight road ?
If the springs were degraded and needed changing then maybe the suspension bushes also need changing or upgrading.
How far have you lowered it?
I'm not familiar with your particular car but lowering normally affects the steering geometry as the steering arms are will be at a different angle to what they were when the suspension was higher.
You cant often get away scot free by just lowering stock suspension as the lowering process affects other aspects of the steering and suspension. So you need to make some other adjustments to compensate.
Give us some more info as per the questions above.
Perry