My cat has become very frightened

She started acting up like this a week ago...Started when she jumped down from the window scared and ever since simple noises make her jump...yesterday she pee'd in our bed and poop in my bed sheets.....She stared on things and starts pawing my daughters shoes and walk slowly like shes trying to be alert every time with huge pupil and long body down to the ground.I am very worried coz my husband wants to get rid of her now if she wont start being normal and vet is too expensive for me.

Any advised would be wonderful.

It always good idea to check in with a vet as there may be something medical going on

Sounds like something scared her, does she go outside? Maybe there cat or something that bullies her and seeing them cause a reaction.
was there any loud noises when she got scared?

How old is she?

Read these article if you can't afford vet care
http://www.thecatsite.com/a/when-you-cant-afford-a-veterinarian
http://www.humanesociety.org/animals/resources/tips/trouble_affording_veterinary_care.html