Please help me my car wont start
 

Ok so this is what happened. I have a 2001 ford explorer limited. I didn't have work the weekend of feb. 12-14 so since it was freezing i stayed home, hench not using my car. Then i had plans for the 14th but when i went to start my car it turned out that the battery had died. A friend came over to jump start my car, then checked the voltage of the battery, said it was at 11.5 when it should have been at 14.5, meaning the alternator wasnt charging the battery. Said he knew how to change it. Bought the part, he changed it out, the voltage read 14.5 so he said it was good to go . We let it run for a bit and then i drove it to the store. I had noticed the check engine light was flashing and there was a rough vibration while i was idle. I asked if that was normal he said yes, since there was a new part added, it should go away in a day or so. Then next morning i noticed the battery light on the dash flickering, told him about it, he said he would take a look. He changed what he called a "pigtail" it was this thing that plugged into the side of the alternator it had a green and yellow wire with a black tube taped shut around them. I had mention the check engine light was now always on. I knew i need an oil change but needed to wait a day or two for my pay check to come in. I asked if maybe that could be the reason. He checked the oil said it was kinda low and there was a bit of white foam, told me to put more oil in it and i would be ok. Drove a round the test of the day, on my way home that night, i was on 287 going about 70mph. Then my car slowly decelerated to about 45-50mph. Not knowing what else to do, i stepped on the gas pedal a bit harder. The rpm meter shot up pass 3 and then dropped back to 1, then my car started accelerate back to 60 but wouldn't seem to go and faster than that. Once i finally got home, just as i turned into my driveway my steering wheel locked up, the engine just turned off and white smoke came out of my hood. I tried to start up my car again and it cranks and sounds like it wants to start up it wouldnt. So i pushed it into a parking spot, hoping that maybe in the morning it would work but it didnt and still dosent. Today i had a friend with a obd2 scanner, i think its called, came over to see if it spit out any codes and it showed the code p0302, which i think he said meant that the 2nd cylinder was misfiring? Does anyone have any idea what could be wrong and if its possible to fix or if its even worth fixing. Please...

It sounds like oil and water has mixed in your engine and it may be toast. Check your oil and see if it is a milky brown color, like my attachment.