03 maxima trans code 0732, sometimes no excell. in drive??

I have about 77k on my 03 max and the other day when the light turned green I pushed the gas to go and there was no response what so ever. If I put the car in neutral, it revs fine, in drive, nothing. This has happened several times in the past week and the S.E.S. light came on to. I had it checked and I was told it is code 0732, B.T.W. I also have the harsh shift from first to second. internal transmission failure/incorrect gear ration in 2nd gear. Is it just a coinsidence that I added a transmission additive 1-2 days prior to experiencing this trouble? Is the computer keeping my car from going? I asked for the Trans. to be flushed in hopes that it would help.