I'm going to retaliate by singing in the dorm bathroom
How is singing in the dorm bathroom retaliating?
I'm going to wake up my roommates with my singing.
It is very rude and petty to bother people with noise, and it will just cause them to dislike you. Instead of waking up your room mates, you should talk to them about your issue like an adult and if you can all be civil, then they will listen to you. If you wake them up by singing, then living with them will just become more awkward.
But I'm in a really bad mood.
If you're in a bad mood you should just step back from the situation for a while. You should talk to your roommates instead of annoying them with noise; what if they decided to get back at you for that and make things worse?