2003 Chevy Impala fuel injector

03 all black impala 3.8liter v6. Worked fine, checked it every day for water and oil and everything. No problems until the winter in colorado came. First my heater went out. Then my water kept getting drained for some reason. I still had anti freeze tho. It was full but no water. When this problem happened I had just drove 60 miles, then my check engine light came on and my car started to smoke so I read the hot guage and it said 260 then went down to normal and quit smoking. Then I tried to accelerate above 60 mph and I lost power and my speed started to rapidly decline eventually to wear it wouldn't go at all. Then I attempted to start it and I had to keep pushing on the gas pedal to get it started and to keep it started. Help?