Hey guys, out of the blue my toilet will not flush, my tub and bathroom sink will also drain super slow. When I use the shower my toilet will gurgle. I got a cheapo hand auger from walmart and that went 15 feet and got what felt like nothing. If I plunge the tub water will drain from the toilet into the tub and vice versa if I plunge the tub. When I plunge the toilet the water level will go up and down in the bathroom sink. Any suggestions or ideas on what to try. House was built in 1950s and drain lines are cast iron (besides shower, toilet and sink pipes) thank you!!