2000 Stratus won't start

A little bit of history on my problem. It all started about 2-3 weeks ago when the car got hot and I noticed it need coolant. I added coolant and then realized that I had a small coolant leak which I think was coming out of the water pump. Since I didn't have time to fix it, I just kept adding water and coolant, checking that the reservoir was always full. Car would run fine and the temp gauge never read hot (except for the 1st time 3 weeks ago). Last night I was driving on the freeway when I started loosing power and the car just shut off. Smoke came out from the engine compartment but not any from the rear from what I could tell. I got pushed off the freeway by the CHP. The car will not start anymore. It sounds like it wants to but no go. Sorry for the long message. Any ideas or tips? Thanks