What would you do?

Okay, so it gets really hot in my room, especially at night, and I've informed my mom many times this Summer, but she doesn't seem to care, and also, she comes in whenever she wants (using the key) and I don't like it when people invade my privacy like that (especially when I'm sleeping), so I duct taped the doorknob on the outside, and she walked by while I was doing so and flipped out about it, and she says she has the right to come in whenever she wants, and I say not when it's my privacy she's invading. So, I've been taking these pills I got from the doctor for anxiety to sleep, since it's too hot in here and I can't sleep. Well, I can tell they're ******* with my head (and my heart), but it's the only way I can sleep, and I'm getting really pissed off at my mom, and I'm afraid that if she takes the tape off the doorknob and comes in unannounced again, I'll do something stupid (like smack that *****). What's a more permanent way to jam the keyhole in the doorknob?