I second everything everyone has said and just wanted to add this:
You are an amzing friend to all of us - you always have a kind word, a sound opinion and a helpfulness that I know makes all our our lives easier. You deserve to be happy and to be able to enjoy the experience of planning your wedding. It doesn't all have to be done right now - seriously it really doesn't You can literally wait until a week for the wedding to decide what cakes to get! Is there a night or day or sometime (any time) this weekend or in the next few weeks where both you and Cain have some time off?
I thinkyou guys should put everything to the side for a night/day and go do something fun and light-hearted - ice-skating! snowboarding! a romantic dinner, a movie, anything it doesn't matter what. Jus the two of you and before the "date" starts you both agree that this will be all about fun stuff and no stress! That means no wedding planning, no Marty (b*tch!) talk, no dog talk (poor little guy!) just you two havign fun and remembering why you're together ad getting married in the first place.