Calling all plumbers?

I've tried everything short of calling a professional and I can't get my tub to drain. It does, sort of, it's just really really slow. I'm not sure who put the pipes in our house but the drain from the washer, the bath tub and the bathroom sink all connect to the same two foot section of pipe. The sink seems to be draining fine but it could just be flowing into the length of pipe from the sink to where it connects to the bigger pipe. The washer is backing up into the tub and the tub is just not draining. I've tried using a wire to clean out the pipe but the best drain to try it in is the tubs, and its really difficult. I've tried using liquid plumber but that doesn't seem to have worked. I've even tried crazy online remedies but that hasn't done anything either. I can't afford to have someone come look at it and I don't want to have to replace the pipes. What can I do?