1997 Ford Mustang 3.8 V6

Just got a 97 ford mustang 3.8 v6. Everything was
good drove smooth until yesterday. My car began
to over heat. I pull over let it sit and see no leaks. I
have plenty of antifreeze as well. I wait for to cool
down then try turn back over which it would not
turn on. The car sounded like it was about to turn
over then give up. A random person offered to try
and jump it and it turned over. I brought it to auto
part store to hook up the battery which checked
out good then hook up the computer and it showed
a bad cam sensor. I replaced it and it turned on
immediately. Brought it home. Today my car
overheated again and check engine popped back
up. I was told my car is running lean in bank 1 and
2. My car again wouldn't start again. Somehow I
got to turn it back upon and drove it home. I have
also realized when i am at a light and stop my idle
drops very low and almost stalls out every time. I
have sat to see if it will stall but it does not. It
jumps a little up and back down like it will stall
again. When it feels like it is about to stall from
having a low idle it makes a knock sound. It will not
make the sound unless the idle is very low. And
now my car hesitates before driving. It does not
jump but just takes a couple seconds before
moving. Any help?