Get a new doctor. I had my daughter at age 26, then bled for a full month, rather than the more normal week after giving birth. Then I didn't have another period for over five years. I had mood swings, hot flashes, dry skin, pain on intercourse, even arthritis symptoms in my hands to the point where I had trouble opening a car door.
After a couple of years, I had blood tests done, too, and all was "normal" except an underactive thyroid. (Why did I wait so long? Fear.) Started thyooid replacement, but didn't see any changes. Slowly, other things started happening, and I don't even remember them all now, but eventually, I no longer needed to shave my legs or under my arms, I was losing head hair, and what really scared me, my breasts, which had always been very full, were literally going away!
I got scared and went to a different doctor, shared my symptoms, and had an exam and more blood tests. The doctor said, and I quote: "I find two things remarkable - the loss of hair, and that your uterus is very small and hard like a child's." When the blood tests came back, she told me that I was very low on both estrogen and progesterone and that I needed to be on hormone replacement therapy at once, or I would age 10 years in the next year.
I'm now 52 and still on the therapy - I wish I had been able to start it sooner - my daughter got the brunt of my mood swings, and my poor husband was afraid to touch me because of the pain I was having. I never quite made it back to what I feel is normal, but I'm so much better.
I had experienced "primary ovarian failure," the medical term for what causes menopause. At somewhere between ages 26 and 30, I went through menopause. You're not too young.