6 years difference when you are 16 is more than ⅓ of your life to date. You still have a lot of growing up to do, and you may find that you will grow in a very different direction that you or he expect. At that point it could turn out that the two of you no longer share goals and approaches to life.
It is true that there are relationships like this that result in life-long marriage. However, many more such pairings result in divorce, especially today when we all seem to be aware of many different options in our lives, and no longer pick one thing and stay with it.
I must confess that my paternal grandmother was 16 when she married my grandfather, who was 30 at the time. However, they only had one child who was sent off to school, so she was able to be the “little girl” and he the “daddy” all of their married life. Unfortunately, this meant when he died long before she did, she was totally unable to take care of anything outside of housework. She could not balance a check book, do her taxes, or even drive a car. In other words, she solved the possible problem of growing apart by never growing up. She stayed a 16 yo her whole life.
Now my husband is also older than I, but we married when I was 35 and he 46. We had both established our careers and goals in life and so were less likely to grow apart. Unfortunately one of the problems with this age difference is that at 67 he is a very old man (he has been disabled for many years) and I am his caregiver, and not so much his wife.
Don’t do anything rash, and if the two of you do grow apart, figure out a way to remain friends even if you can no longer consider a life together.