If your PSI is 0 and you have air in the pump basket, the impeller and pump should be ok because it is pulling water out of the basket and air into it. This usually a good indication of a blockage on the suction side.

I know you said that you tried to clear it but perhaps your first try was not successful. Although a rag around the hose to try and clear but this does not always work well. I would get a drain king from the hardware store for your pipe size and try that. It allows for higher back pressure than the hose and rag trick.