2002 Pontiac Grand Am not sure if I have a brake prob or ti

I have lost control of my car 3 times in the past winters and I am now gun-shy of my car in the winter. I havent been able to get a straight answer, and since it could be a variety of things I am afraid to get it repaired not knowing if it will fix the problem. I have a perfect driving record, so its not from wild driving, if anything I have always babied my cars figuring I am the one who has to pay for repairs, so go easy on the car! lol. The car loses control and has that magic carpet feeling, and will slide, depending on how bad the weather is. today it was lite misty rain, and the car did it again. any car i have ever had should be able to drive in lite normal rain, this car just wont stop. today the abs came on, and when it did, it just didnt stop the car. mechanics have said its the tires, or it could need an alignment, now i am thinking abs (no lite has ever come on), If I went and bought new snow tires thinking that would fix it, i wouldnt be able to tell if it fixed it, until it rained or snowed again. This car wont even go thru the tiniest pile of snow, its just feels like no power to the front.
This car is 6 months from being paid off, and i enjoy it in all other ways, but it is a major safety hazard for me and my kid. please tell me what you think it might be...I really appreciate it!!