'97 in need of some help

[Thunderlover]

Hello fellow Thunerbirdians i am in need of a diagnosis for my '97 Thunderbird LX (V6).

The other day while driving i came to a point where i had to gun the engine a little more than usual. Usually i try to kep the RPMs from going past 2000 and my car will usually shift around 2000-2500 RPM, but in this case my car didnt want to shift untill around 4000 RPM, and when it did shift my car became sluggish and heavy white smoke began pouring from my tailpipe, although i was moving so maybe it came from the engine and traveled behind me to make me think it was coming from the tailpipe. anyways after that my RPMs had trouble staying above 500 and it normally idles 800-100 and it was feeling very rough. very shortly afterwards it was working normally again, but the next day while running errands i tried to start my car and she failed to start, i repeated this 4 times until she stayed on but the moment i put her in reverse she just clicked off. the next time i got the engine on all the way i revved the engine to get back to 1000 RPM and put it in drive and she started moving and i got her home, i havent drove her since, which was 2 days ago, im worried about my car, its the first car ive ever bought. being a college student i dont exactly have the money to run her to a mechanic to get her fully checked out. this isnt the first time my car turned off when going to into reverse, i can usually tell when its going to since the car will have a rough start. if it can help at all my check engine lights is on for a code P1443 which is for a Fuel evap error, but hen it initially came on i felt nor saw any performance issues, any help and opinions would greatly appreciated fellas, thanks -Thunderlover

UPDATE: i drove my car to work this morning, started right up but idles rough when in gear and unless im accelerating it stays rough, afterwork i got home fine and checked to see my coolent level was low. could that be the reason for all the white smoke? this white vapor/smoke was pretty thick and ive had performance issues ever since seeing it. all the car isnt shifting as smooth.

UPDATE: Upon further inspection i have found that i have a cracked water jacket, will this affect the RPM's and shifting?