If you think that marriage is the 'Happy Ever After' then YBNU, it isn't. It's the start of something that will only work if BOTH put masses of hard graft into it. It's not always fun, it can be a battle, but if both of you are on side, I can honestly say it's bloody worth it, I've only been married 13 years, if it endedtomorrow it would have been worth it.
It would also have been 'worth it' just to be his partner, but from experience, our wedding day is one that gets us through the sad times as it was 'us' at the centre of the world (the ceremony of that day should never be underestimated) and our vows get us through a lot of doubtful times, the legality and binding of the law makes us dig deeper, not just because it's about what we could lose but what we'd get too!!! 
If you think of marriage as the start of a new story, not a chapter perhaps, but a volume, then YANBU to think that many stories end in gloom or depair. Few have 'happy endings', it's never fun to watch your spouse die, or think about dying before them. However, some can be said to be 'a life well lived with love'... my Gran and Grandad, 54 years, my FIL and his wife, 47 years until she died, but it was stil worth it.
You can get to happy ever after and add 'then it all turned to shit', that's you story, and there's far too many innocent victims of that. Or you could be actually lucky.
I don't live in a fairytale, but it started as one and reality is satisfying even if it's not so exciting as the unknown. Knowing you've promised everything to someone is profound.