I do know rather a bit about witchcraft, and what he is doing is not good at all. Witches and Pagans get a bad reputation for things like this. Most witches follow white magic, which is basically using the energies from the earth, nature, Gods, and their own spirit to bring positive comings to themselves and others.
But some people use it for quite the opposite (black magic). Remember the law of witchcraft is whatever you do will come back at you threefold, so he's going to cop it one day for what he's done to you.

I had a bad spirit in my house a few months ago, I was so terrified I would barricade myself in my room at night and couldn't sleep. It went on for weeks and weeks until I couldn't take it anymore. So you know who I went to? A witch who did white magic. They had a real concern for me, especially when I told them I couldn't leave my room all night and actually seemed really shocked, so they were more than happy to help. They told me to burn a smudge stick (I can't remember what herb it was), then burn white candles while calling one of the Archangels to help whoever it was leave. And you know what? It worked. My next attempt would have been a priest but lucky I didn't need that.

Don't let this experience turn you against all witches and Pagans, on the most part they do not do things like this. They are very spiritual people and I've always found them to make me feel very calm and safe whenever I'm around them. Try what the person above said and if it doesn't work you could try what I said (I can try and remember fully what it was I did).

I have no judgment on anyone's beliefs and am open to every possibility, as long as it doesn't harm others.