Converter Slip?

I was parking my car today and was rolling forward at about 5mph and dropped into reverse like an idiot, and then heard a couple of clunks. The car has felt less firm on the shifts since then and drove it at WOT and it was fine and has driven fine since.

A few minutes ago, I punched it to see if all was well from about 10mph... the car dropped into the lower gear, then the revs went up to roughly 5k rpm with the car accelerating(felt like it was accelerating at a 3/4 throttle pace), then dropped in rpm's and sprung forward like the converter had just locked up and flew like a bat outta hell and didn't do this for any other shifts, only the initial drop. Is this converter finally on it's last stint? It's a built 5R55S with a POS TCI 3000 Stall, your input will determine my next move, thanks in advance guys