Q: Will I need to buy a new transmission?

My husband tried to change the oil for his first time and he accidentally took off the transmission panel and let all the transmission fluid out, he thought the that was the engine oil so he put the panel back and poured 5 qts of oil in the oil holder where there was already the bad oil that he didn't drain. We thought all was good so we went for a drive to test it and the car was not catching gear the RPMs would go up but there was very little speed. So we went back to Pep boys where we bought the oil and they said we drained all the tranny fluid out so they told us to buy 5 qts of tranny fluid and we poured it in right away then they showed us where to drain the engine oil from since there was double what we needed in it it was vital that we drain it right away so we did and we replaced it with the 5 qts of good oil but the car got worse and now it doesn't catch any speed at all! What do we do ? We drove around with no tranny fluid for approximately 30 min.

My car has 85000 miles.
My car has an automatic transmission.