You say you just shelled out who-knows-how-many-hundred dollars in tires, had them mounted and now the car feels like crap?
What you need to do is have the car properly aligned and the wheels balanced properly. But first you have to rule out any problems with worn or broken soft or hard parts. Don't even bother to try to waste money on an alignment if you don't fix worn or broken things first.
If you've had somebody look at it already, find out exactly what parts they wanted to replace. Phone around, and get the best price you can for these parts.
Find somebody more reasonable price-wise. Have them install the parts.
I pay $99 for a good 4 wheel alignment by Dutch guys that understand European cars. I also pay $50 have the tires balanced on the car by an old guy that does it by spinning the tire up and feeling fror vibrations on the hood with his hand. Sometimes he gets cranky and it's another $20 to make him smile instead of swear at a particularly difficult wheel.
Do this and now it should feel a lot closer to new.