I am 45 years old and noticed some changes to my body the past year and a half. My periods are regular but PMS is brutal, sore breasts, water retention anxiety and moodiness. It has not helped that the past year I have gained over 27 pounds and went up 2 dress sizes. I have always been petite framed, hourglass & slender with a tiny waist. I remained active my whole life..daily swimming, running weight training at lunch, long walks with the dog, and running around with the kids the rest of the day. I have always watched my weight and been a healthy eater. All of sudden I have blown up!! II bought new clothes last year when my old ones didn't fit now my new ones don't fit! My shoes and boots don't fit(some really nice ones!)!! 
what the heck? My coats don't fit, bra is too small...pretty much a whole new wardrobe! I Feel very unattractive & no matter what I do I feel like I can't fix this. I am embarrassed about the changes to my body around my husband & when we have sex as I feeI ugly. I know my husband loved my body and showing me of to his friends. Our love Is more than this I know but I don't remember the last compliment he gave me and he doesn't want sex like he used to.I have avoided some social events as well. I have always gone to work events with my husband, dressed up, had fun, flirted, but have stopped doing this as I dislike the "new me" that has seemingly happened overnight. I just can't enjoy things like I used to! I also fear more changes are coming when I head closer to menopause. I am irritable all the time & don't know how to accept these changes. Am I doing something wrong? I have had an under active thyroid for 16 years and have been medicated. My levels are normal so this does not explain the extreme weight gain and body changes. I asked my doctor if this is menopause and she said I was too young!? I am 45! Are these symptoms normal & is there anything I can do to feel like myself again!
Yes I kind of blew up in my 40’s for a while don’t worry it will level out . I went back to my old size 4-6 then at 51 I lost 25lbs and looked anorexic ! So it’s all hormones and it goes up and down . I love being skinny but the MOST IMPORTANT thing is mental health. If somebody loves you weight is unimportant I’m in the best shape I’ve ever been and I’m single and lonely so ... go figure !
I'm 46 and going through a lot of the same things as you. Find a different doctor. Perimenopause can start as early as your early 30's.