Need advice major issue

I have a 04 rx8 was driving down the road and it over heated i mean straight to redline turned it off immediately pulled of the road let it cool threw some coolant in it the next day it wouldn start so i tried to deflood it finally got it started but it was running really rough tried to start it the next day and it was like the ecu was not letting it even crank so its set for like two weeks decided to mess with it got it started but it was blowing smoke like i have never seen there is a coolant leak now but i cant find it and theres a pretty rough tik i took it around the block to see if there is a power loss and there isn't so i have no idea what is wrong it has 92,000 miles check engine light is on oil is good please help