Stop moving start making some loud revving sounds?

I bought my vehicle listed above a couple months back and drove smoothly. Every time I turned it on and went then one afternoon my car decided to start making some loud revving sounds and completely will not go faster than twenty-five miles per hour. Go about 3 blocks and it completely stops moving. No drive forward no drive backwards nothing turns on like a dream still and sounds like everything is okay, but it obviously is not. Oh, I got it to move forwards for a brief second before it never moved again. Please anyone, I could use help because a mechanic I am not. And will take all the advice I can get from anyone who is knowledgeable.