I'm not attracted to my wife now that she's gained weight
Is her weight gain the main reason you aren't attracted to her anymore?
I can't stand these extra pounds she put on, I don't want to lay eyes on them
Attraction can be complicated but you should consider how your wife feels. She will feel hurt that you don't feel attracted anymore and it will hurt your marriage.
It doesn't matter since my wife is curvy other people don't notice the extra weight like I do.
If you really don't find her attractive, suggest a new and active hobby for the two of you to do together.