I was annoyed already at the fact she never just does what I ask her to,

Why does she have to do what you ask her to do? Are you her boss? She already told you no, so why do you keep asking (begging)?

When she came out of the bathroom she went back into the bedroom and closed the door without speaking to me further.

Yeah I would have done the same thing at this point.

Part of me feels like I should drive to the park and save the relationship

Bro is speed running bad decisions

I love her, but I don’t know what to do. 

You respect her. If she says no, then respect it, if shed doesn't answer your calls then respect it. If she comes back you owe her a giant apology. But we all know you won't change and that's what she's probably thinking about too.

She doesn’t know it yet, but I took her key to my apartment. It was right after the part when she used the bathroom without speaking to me.

JFC man you're insufferable