june.sky, I would say your assumption of over watering is probably correct.kiwi plants do not like damp conditions at all.how often are you watering?a good finger in the soil is a easy way to see if there is adequate moisture,as long as the soil has moisture and is not bone dry your plants will do fine.My advice is to stop watering and only water as needed,make sure the drain holes in your pot are free flowing and hopefully the roots are not completely rotten.Even if it recovers a little bit, it is quite late in the season now and it will probably not make it through the winter if it experiences really low temps(not sure what zone you are in).I have kept potted kiwis in the fridge over winter and planted them out in the spring...You just need to put it in spot in the fridge where no one will get mad at you:)