The age of menarche (first period) has nothing to do with the age of menopause. It is very possible you are in pre-menopause and experiencing your first shift in hormone levels.
You will most probably have some more periods, because they seldom just stop suddenly.
Hormones tend to shift for a while before actually going for good. I would suggest taking Menopause from A.Vogel to help with your night sweats as well as to help to prepare you for the hormonal balance in post-menopause.