It's not going to change a jerk into the man of your dreams. It is not going to make your SO give a damn about your child when he already has 4 kids he doesn't see. It's not going to make the guy who treats you like crap suddenly love and respect you. A lazy guy isn't going to work harder. The loser who lives with his momma isn't going to become Bill Gates because you gave it up.
It's not magic.
Start with a decent guy to begin with.
That is all.