Can I think about my cat every night?
Sure but why would you want to think about that every night.
I have been spying on her when she is in my bed sleeping with this stupid lovey-dovey attitude. I cant stand it any longer
It is ok to get emotional when you are attached to pets. You should not obsess over what your pet is doing if it interferes with your life.
I'm going to slowly stop feeding her until she passes away.
That's a harsh way to get rid of a problem. If you can't stand the cat's clingy-ness, why don't you just lock your bedroom door? There is no reason to kill your pet because why get blood on your hands when you can just send it to a pet shelter?