ultranewbieidiot4000

So I did the drivers side head gasket and now im getting giant clouds of white smoke out of the tail pipe and unburned gas also. Yes I already checked the timing marks several times. Also played with distributor timing quite a bit also. Spark, yes. Gas, yes. air, yes. But right now only a ton of throttle can get the engine moving and it wouldn't even have a chance at idling. No idea what to check next any tips would help.