live it up!

My brother's car was acting really weird. On the way to class it was perfect, had the AC on and it was smooth sailing. On the way back it was a scortching 91 degrees. I turned the car on, turned the AC on high cold air then pulled out of my spot. Two minutes later whenever I stopped at a red light the car wouldnt go fast, I pushed hard on the gas and it went 20 miles per hour. It was a 35 mile per hour zone. I went up to blocks and the gas wouldnt worked at all. So I carefully pulled over into a parking spot about ten feet away. I sat in the car turned the AC off, and just let it run for a while. Five minutes later I pulled out of the spot and it was fine for the next 7 minutes. After some time with no AC it was scortching hot (keep in mind this is a black car and its very hot inside). Anyway, I turn the AC on and I stop at a stop sign, I push on the gas and the car jerks. I turn the AC off, open all 4 windows and the car is fine a minute later. I turn the AC 3 minutes later while I'm on a back street but dont have it on high, its on 73 degrees. Then the car was fine all the way home. So weird. The car has never given me trouble before, ever. I am clueless about cars. I am thinking I should take it to the car shop and have it checked?