I would love to help you on this, I have a set of OEM IS-F from my 08 ISF. they would make your car rise up like a truck, due to the fact the springs are meant for a heavier car.
Now that you have aftermarket lowering springs, have you checked if you have the OEM shocks/struts?? if so they might be leaking, or just simply worn down. You may want to just upgrade your struts/shocks to some tokicos or buy a whole new coilover system.