White smoke from exhaust pipe

I just recently changed my radiator. I had to ride with the old one busted up until I got the money to do so. I had to put water in it every time I drove it, and I would only drive to work and back. It over heated pretty bad one time, since then I wouldn't let it get past a certain degree. But it ran considerably warmer than usual all the time in between then and the replacement. My tailpipe now has white smoke coming from it.
Also, I'd say once a week, the engine would jerk when I attempted to crank it. Now it won't crank at all. I have an exhaust leak where the head pipes and catalytic converter pipes meat. It looks like steam due to its wet on the areas it sprays on.
That's about all the information I have of the top if my head. I really appreciate your time and I really hope this issue gets resolved.