Air conditioner not cooling properly

So I bought this car a couple months ago so my girlfriend and I would have a four door car for our son that were expecting any day now. After I bought it I notice that when I would "punch it" or drive up a hill it would act like it didnt have the power to get up and go. The only way I can think of is, it would surge, cant really describe it. The I started noticing that there is an awful of white smoke coming out of the tail pipe, even when its not cold. I do not smell a sweet smell and the oil is not milky or anything like that. So I was wondering if anyone on here could help me figure out whats wrong or have any ideas of what it could be. Thanks in advance

2000 Chevy Malibu 6 cyl

My A/C has had issues for years. It has 1-5 settings. At first 1 and 2 stopped working. Now none of them work and the control panel doen't even lite up. Unless my wife kicks the consol in the passanger side floor board and then only for a few minates. When it does work it blows really cold air, but 1 and 2 still dont work. However it only stays on for a few seconds and stops again. What could this be?