1996 Toyota Camry Transmission: delayed engagement

The transmiission engages a few seconds after deressing the gas pedal. The problem is only at the start of the car from a stopped positon. Once the transmission engages, the car runs nomally. This happened once in a while before but now iit is getting worse. I just changed the transmission oil and added some tranmission fix fluid but did not notice any change. I have not changed the transmissin filer in the past several years. The car has been running fine for the last 11 years I owned it. The car also developed another problem now. Whenever it comes to a stop sign the engine starts stalling and then stops, unless I keep the gas pedal depressed slightly. I am sure it is time to retire the car but I like to keep it a little longer if there is a cheap fix to these problems. Please advise