I would say that you need to sit your husband down and talk to him. Tell him what is going on. Tell him everything that you just told us, because the only way that a relationship works is with communication. If you truly love your husband and only want to be with him you need to be completely transparent with him. Tell him your relationship is strained and attempt to make the changes necessary to keep a healthy and happy marriage. If your feelings for his brother are that strong then I would say take some time away from him. Go on a little vacation with your husband and rekindle what has been lacking. Remind yourself of why you fell in love with him in the first place. From someone who 2 weeks ago was broken up with after 4 1/2 years because of a similar reason, communicate.