ok so it all started with a small leak in the radiator hose, about 2 weeks ago, my car overheated because the leak pretty much hemoraged making the coolant water non existant

so i replaced the head gasket and radiator it was still driveable but still idleing a bit rough

i've ahd problems with it dying on me while i was stopped but usually just had to turn it on again

today it died on me and it took 2 tries to get it going again, luckilly i made it home fine but while going up my driveway it died and i couldnt get it idleing smooth enough to put it in drive (becasue it died in drive)

i looked in the coolant resavor and it gushed out (i think it was becasue it was still hot) and it look like their was oil or somthing like that in the water

i dont know whats wrong or what to do, help!?
4 cylinder