trying to get my truck going can any one help

Is it cold we're you are? Because my truck is doing the same thing and it's very cold we're I am and I was told to try dry gas to help the gas lines and that should help u out to. As for the oil I would check your head gasket to see if it's like a chocolatey color and consistency if so u might have a blown headgasket. But I would recommend doing the dry gas first before anything. It's at any of your local auto stores