About your question :
It's wrong to say : I do not wanted .
The correct sentence is : I didn't want to .
The difference between the sentences :
I didn't want to (This is past simple)
I do not want to (This is present simple)
For the second :
After (did) you have to use the verb in base, You can't say (I didn't wanted) - So you have to say (I did not want)
P.S/ Not a teacher, But i think this is the truth .
Hope this helps