Underbody Shield problems of the 2003 Saturn VUE

As I was driving my and it car began to pull to the right and the tires began to squeal. In my mind I thought I thought I needed better tires and a wheel alignment. As I was driving to get the tires and alignment I heard a cracking from underneath the car, this really scared me. At this point the pull to the right was even stronger. I arrive to a tire shop and put tires on thinking this would be better but it was the same so I drove across the street to a mechanic to get a wheel alignment and the mechanic came out and went underneath the car when he came back up he stated that "your subframe and chasis is cracked all the way through, park it immediately for safety reasons, in his 20 years of experience as a mechanic he only saw his twice the first time was in another car that was recalled and mine that should be on recall with the level of danger, especially because I see you have a baby's car seat in your backseat". He also said even an older car should not have a subframe crack like this, and that the motor can fall out while I'm driving and the wheels will collapse. What am I supposed to do I can't even trade it in and it's worth $5500 and the cost would be fananimal to fix. I can't get to work and even child car this is horrible. Please help. This is a defective car and the worst I have ever had.