Transmission or engine

I would this happened to me this morning but because of the cold my rad ended up being the problem. My car after that point kept slowing down no matter how hard i pressed on the gas and then eventually wiouldnt go faster then 10 km/h so i pulled it over and then i couldnt get it moving again

Do you have any check engine lights on? What at the engine RPM's running at when traveling 45 mph? if so then we should scan and look at the stored codes and data, this could be many things,some very simple some not. With about 20 minutes of diagnostics you should have all your answers. Number 617-387-9558 Everett MA