Hi Missygreta.
The person in this link is a Cat behavior specialist, and a lot of good reading.
What works for my cats, may not work for yours, as they are all different.
Your cat sounds very stressed to me. Is it ever let out?
A cats natural environment is not locked up in a house all the time.
I have one that gets quite stressed. I take my cat out in the garden for 20 mins each day at round the same time.
My cat comes back in completely calm, relaxed and goes to sleep.
Every day around the same time, she meows and lets us know it's time for her stroll in the garden.
I hope you can find an answer to your cats behavior.
Cats are natural hunters, and my guess your cat is pretending her toys are prey.
How to Stop Play Aggression in Cats