I think your doctor is right - the peri menopause is a major factor. It happened in the middle of your plastic surgeries so instead of your hair growing back, you lost more. And many woman dont realize but peri menopause can actually last 10 years, so you were probably in peri menopause for the past 5 years which made things worse.
It isnt possible for the hair you lost 5 years ago, if it started to grow back with that year to still be growing back unless it just started coming back this year. Hair cant take 5 years to grow 8 inches - your hair isnt that long and you do get your hair cut, you have probably had more than that cut off in the past 5 years, so what you have now is all new hair. You might still have new hair growing that will eventually make it thicker which a very high protein diet should help. Sometime other minerals can cause hairloss like zinc, copper and I am not sure what else. There are many homones that affect it which caused me to lose alot of my hair starting in my 20's.
My younger brother had 2 knee surgeries when he was 13 and 21 - they were major reconstructive surgeries. When he went into the second one at 21, he had a full head of beautiful hair and with 6 months, he was almost bald - like a 50 year old man -all around the edges. they said it was due to the anestesia and stress of the surgerie and didnt know if it would ever come back and to this day, he is now 47, it never came back. he tried hair transplants at 25, nothing really worked. Some people, once it is lost, the hair folicles just dont come back to life.
I couldnt believe mine came back - 1 year ago, I had a few strands and now it is better than it was before I went into my surgeries (1 1/2 years ago) Dont get me wrong, you still have 10 times more than I do on top - I will always look balding on top - that will never come back - I lost that 20 years ago and there are no folicles to grow back but I am happy with the back coming back.