I'm thinking of my girlfriend constantly cleaning my apartment
Why would your girlfriend feel the need to constantly clean your apartment?
She has an obsession for cleaning my apartment. It's very annoying.
If you notice that your partner is behaving in odds ways such as compulsively cleaning over and over again, you should try to get your partner help and support. Your partner may have obsessive compulsive disorder. You should talk with your partner and say that you are concerned about her behavior and that she should try speaking with a therapist to help address her need to clean constantly.
What if I get insane and tells her to stop or to just listen.
Well you should want to get your partner help simply because you care about them. Try to be selfless in this situation because your partner spending so much time cleaning is most likely not their ideal situation.