nissan micra 1993 kangarooing and loosing power ?

NEED HELP PLEASE!!!
I have a 1993 micra. It began with rough idle, car turning off at stop lights, exaust smell, lost of power. Took it to my the mechanic, initially he didnt know what was wrong, eventually he found a fuse which had rust, cleaned it and the car for a few days worked great! but eventually whent back to the same. I've read that Micras have problems with the Air mass meter/Throtle body, I mentioned this to my mechanic, he inspected the car and founf a loose plug connection that goes to the throtle body, again car worked great for a few days, but whent back to the same. Couple of weeks later out fo no where the car began to KANGAROO, intermiten jumping, which would get worse and worse once it started to KANGAROO, to the point where you would loose all speed. Eventually i noticed that when the car is cold you have about 30 minutes before the car start to kangaroo, also, notice that once if posible, I get the car above 60 kmh in a long drive without stoping, the car drives great again!!
I dont know what to do anymore, am a medical student, and I really depend on this car, but I am also on a tight budget so a different car is not a real option. My mechanic seems to be at a lost..I was thinking of replacing the Air mas meter/throtle body????? Any sugetions, comments please !!