The marriage of a very good friend of mine is in trouble. Eventually my female friend persuaded her husband to seek marriage counselling. He agreed when she pointed out that it would benefit their child. After seeing them both together for a couple of sessions, the counsellor asked to see them separately for several sessions. I would think a good counsellor would ascertain whether this approach was needed for you.
I knew when I was diagnosed that with my baggage going into cancer (click on my @ for details) I was going to need some psychological help. I have moved past using the cancer specialising psychologist, to a general clinical psychologist. Which is a way of saying that I think at this point you need to treat the whole person, and the whole partnership.
I agree with what @Afraser and @Flaneuse have written above. Ask your husband to do it with you. If he refuses, go for yourself (all of you, including but not entirely, the cancer). I don't think you'll regret it. Even if your husband doesn't go it will give you some good tools to use in your life moving forward.
Best of luck, and let us know how you get on. K xox