She pushed so hard I couldn't control the door anymore.
That situation seemed tense. Can you tell me more? Why were you trying to control the door?
Because she is always in my space, I never feel comfortable in her presence, she wants to take my place in everything.
It may be appropriate to let her know that you need a little space and time for yourself. This way she won't see getting into your room as a challenge.
She let herself into my room without permission, she's such a bitch. I hate her.
Intentionally trying to keep someone out of your room can come across as a little mean. It sounds like she just really wanted to spend time with you. If you just need your time then you could always be more specific with verbalizing when you want to be left alone.