If there are physical items involved (talismans, or that sort of thing) in your home, you can destroy them.
However, in general, unlike with Amazon, there are no returns in the department of the unseen - it is easier to do than to undo.
If whatever the person did had some effect, and wasn't just fakery, sometimes you can just wait it out as these things can wear down over time.
If you or he are suffering ill effects (for instance, he is not thinking clearly, it has backfired and caused conflict because he is now hyper-dependent, or you have a haunted house now), you could go to someone who is honest, trustworthy, and capable who does ruqya or who can advise you on how to do it on yourselves to help remove the ill effects.
However, that might be awkward to explain to your husband and cause more problems - most people are enraged if they find out someone attempted to do magic on them.
If it is just regret, but you don't have any reason to think there is anything actually harming either of you, it may be better to leave the situation as it is and to focus on building a positive home life and also looking after both of your material and spiritual well-being (religion, health, etc).
In general, regular recitation of Qur'an, regular salat, and playing Qur'an in the background in the home can help to calm down unwanted bad effects and bolster people against the effects of black magic. Of course, praying to Allah for assistance is good.
Sometimes in life we make decisions we regret.
Also sorry to hear about the cheating.
Infidelity and sorcery are signs that a marriage is not at its healthiest. If there are some other underlying difficulties in the marriage, unrelated to those two issues, maybe you could look into some kind of marriage therapy or counseling.
