Well since you don’t want to use demons, you could try a servitor (a spirit that you or someone else creates) for manipulating his thoughts, or look into angels that do that- unless you know how to direct energy and want to do it yourself, though if you made him fear you doing it yourself is probably not the best answer since his subconscious will react negatively to what he fears- you and your energy.
I’m going to make a leap and assume no demons means no djinn either-despite them being a different type of spirit, who would be my next go to. But since I offer you any advice due to your choices, other than to use the search function as this is a very common question…
I will suggest that perhaps making him fear you made it worse, because it probably makes him feel like you are the bad guy or even that you are likely guilty or don’t deserve itor whatever the case is for whatever the legal matter is. Or maybe he just doesn’t like you now, because he fears you.
How does the say going, you’ll catch more flies with honey, than vinegar- or something to that effect?
But I will also mention that demons are no more dangerous than angels, and using demons does not equate to Satanism. I work with many types of spirits, including demons and I have no religion of my own and I am not a Satanist. I know angels that will kill in a heartbeat and demons that heal. They just have a different type of energy and and use their skill sets in different manners 
If you are interested in using a servitor, here is my method of creation, though I’ve heard many time’s Damon Brand’s works really well, and I have good feels about Taylor Ellwood’s as well.