Ive seen stuff about the benefits of marriage, so I thought I'd give it a try. Im waiting on the wedding to start, Ive tried to rest until the time but it kept popping up that I failed to attend the ceremony. So I actually just let the game run until the time it says my follower, Aela, has left for the wedding. Im already in the church, but if fails me, and Lydia, who has been missing for days from random dissapearing, shows up in the church just as I fail, dead. Has anyone else encountered this? Any solutions?

Lydia's corpse appearing at your wedding seems to be a pretty common problem. The only way to solve it is to resurrect Lydia, as far as I know.