If your husband hates witches because his ex cast on him, I don't think casting a spell to keep him is a wise move.
Marriage counciling is your best option. Tell him then, the councilor can keep the peace as a third party observer. Be calm, explain yourself, make him understand you are not like his ex and would never cast over him without his permission because it would be harmful to his will. When done, listen to his side of things, don't interupt, just take it in, think, and respond when he's finished.
Sadly this might end badly. Some people just cannot accept some things. My good friends fiance is Catholic, while she does not agree with Wicca, she let's him practice his faith. He just can't raise the kids Wiccan. My boyfriend is a spiritualist, while not a witch, he welcomes and embraces my views. My other friends boyfriend would say he was fine with her faith, but constantly mocked her for her views so she wound up converting to make him stop. Point is there are many people, many views, if your husband can't find some middle ground, he's not your soul mate. Harsh but a soul mate accepts you warts and all. You may not always agree, but your soul mate wouldn't force you to change something as big as your faith system to please themself.
In the end it is up to you, all we can do is give you advice. You choose your own path. Look within and discover what's more important for yourself.