Ok so my cats back legs froze up and her tail curled up she couldn't walk just fell over what causes this?

My Cat had kittens about 6 weeks ago, now she has diarrhea, she ate a slug the other night, and we are for sure she has ear mites, and just today she had an incodent where her back legs froze up on her and her tail curled up on her back her eyes looked like she couldnt see and everytime time she tried to walk she would just fall over :( any ideas of what it could be caused by?