First and foremost, it's not fair to you that you must sleep on the couch. I would suggest either using ear plugs or if that does not help, going to an ear, nose, and throat doctor as there could be something more serious going on with your husband. Secondly, try to understand where your husband is coming from when it comes to having sex downstairs. The fear of having your child walk out of his bedroom to see you two or even hearing you two can be a major turnoff. I would suggest first dealing with your sleeping arrangements, and once you two are sleeping in the same bed again, worry about how the sex life is going.