Can I just continue to feed my cat everything I eat?
Oh brother, why would you feed the cat whatever you eat? That can't be good for her.
I feed her so she stays healthy.
Even though you want to make your cat happy, feeding her human food could be bad for her or make her sick. You should consider getting her cat food, and get cat treats for when you want to give her a special treat.
We've been doing it for years, she's still fine and has tons of energy.
It could still have things in the food that are bad for cats that you don't know about, and hurt her internally. Onions for instance can kill a cat, and also chocolate. Be aware that cat food has the most proper nutrition in it for cats such as taurine.