My cat is dizzy please help?

My cat is 1 and she had five kittens about six or seven weeks ago. This morning she tried to jump onto my bed, I have a bunk bed, and she fell off. I don't know if this is what is wrong with her though. She can't walk straight, can't sit straight and can't lie down without wobbling. We can't go to the vets because we have no car. She's in a cat box at the minute and keeps straining I don't know why. Please help