1998 Dodge Dakota I think my engine blew

My truck was acting strangley for about one month. Previous to that it had been burning more oil than usual for over a year. About one month ago, the check guauges light came on and the truck would not start. When I put oil in it and let it sit, it started again. Today, I was driving up a mountain pass, and the oil guage dropped suddenly to 0 and the check guages light came on. It stalled at the offramp. I had a mechanic look at it and they said it would be fine. Well, it wasn't. I drove back down the pass and it started making grinding noises. It would not engage into gear properly and took quite awhile to do so. Then it popped and smoke started coming out. Is this from too much oil? The problem is where I live, oil freezes overnight a lot. When you go to read the dipstick, it doesn'e read properly. I checked the oil after the first stall, and it looked too full. What could have happened? How much would it cost to repair?