My husband is 12 years older than I am. It is fairly normal now. If I were 18 a difference of 12 years would be another matter. There is a lot difference in maturity at that point and it is something that you would need to think about. When you want to hang out with people your age, he may feel out of place.

On the other end, I realize that I may end up being a widow for a long time when I am elderly knowing that women usually live longer than men

No doubt two people can be sexually compatible with a significant age difference, but there is a lot more to a life long marriage than sex