While I was showering this morning, the water refused to drain. After hours of it being in the same state, I found out the toilet would not drain as well. The sink, however, does. If the toilet is flushed, it is sent to the bath tub.
Plunging doesn't do anything (I blocked the spillage pipe in the tub as well as the toilet and plunged from the shower, as my toilet has a very unusual hole that the plunger doesn't cover). Using Liquid-Plumr (chemical drain opener) allowed the shower to drain and the toilet to flush until the shower is turned on again. When the shower is turned on, it'll drain but the toilet will start to bubble and fill.
I used a snake and found no blockage from the toilet or the tub.
I found a product called the Drain King, but I wouldn't know how to use it. Could I use it from the sink drain? Will this even fix my issue?
Any help would be very appreciated. I only have this one bathroom; you can guess how inconvenient this situation is.
Edit:
It seems the sink does back up to the shower. I'm having no issues in the sink area itself, though.