Transmission issues!

[Yarisstance]

So i own a 2007 Toyota yaris 4door hatchback. It is the automatic 1.5L. It has been a very good car to me especially in winter. But this morning i was doing alot of driving in the new snow running around town. All of the sudden when i start my car after it being parked for a couple hours i shift into reverse and the transmission started to rattle and make a shitty noise. The noise only happens in reverse and no other gears. I do let the car warm up and i do monitor my fluid levels often. I am praying that there is ice or snow jammed up in the car as i have been dragging on the snow around town. Anybody know whats going on i have a feeling I am losing reverse.