Quite well done

Just a few things:
Ich weiss genau, es ist nicht wahr, doch ich spüre keinen Unterschied
I know that it is not exactly true, but I don't notice a difference [ be careful he knows it for sure, so your sentence gives a wrong sense ]
=> I know it exactly, it's not true, but I don't feel any difference
Wenn du dich mir hingibst
If you give me that
=> When you give yourself in to me
Mach mir ruhig etwas vor [ etwas vormachen = engain someone, not being honest ]
Make me comfortable before something
=> Play a role for me, please
Ich hätt' dich noch nicht verlorn
I
had not yet lost you