1991 Toyota Corolla 2 problems happend same time-air quit-w

Air Conditioning problem
1991 Toyota Corolla Front Wheel Drive Automatic 179, 00 miles

I've been unemployed for 9 mos. And had to scrounge for the $400 spent a week ago on the car.

I had 2 problems occur simultaneously this morning. In driveway put car in park and left running while I got mail out of mailbox. I had been out running errands and was going out again. Air was running on high. (Flat driveway) When I tried to put in reverse the shifter wouldn't move, and button wouldn't push in. I am pretty sure air was still putting out cold. I used the release button and put car in reverse, then into drive. When I used the release button the air stopped blowing cold. I think it was the fan running only. The green air light was still on. About 2 weeks ago I took car to mech. Because it wouldn't keep running. Started but kept dying. Was distributor. He saw timing belt was ready to go and replaced that also. Can you tell me what you think is wrong? I still have to use the manual release button. Thanks