Kate:
Im afraid you have a stoppage in your main drain or sewer line. Youre going to have to find a friend with the tools and knowledge to locate the source of the problem, and auger the stoppage out with an electric ( or manual ) snake. This type can be rented at a local tool rental place, it requires a certain amount of physical effort to complete the chore in a timely manor. If you are a member of a local Church congregation…possibly there is a Plumber or hanyman that can render some assistance with your problem….lots of luck…Bud : Kitchen sink started gurgling than water wouldnt drain properly. Than toliet overflowed and started draining into bathtub. Now kitchen sink seems to be alright, but toilet is draing into tub. What is causing this?