Question to mid-life women?

I am 45. I am 5'7" and have always weighed between 100-110 all my life. 4 years ago I noticed that I was gaining weight. No matter what I've done the weight stayed and my weight keeps going up. I think I might be in early menopause. Over the past 4 years I have hot flashes, retain water, have irregular periods, I'm tired and dieting does not work.I eat the same as I always have done and I don't overeat. I eat healthy. I walk at least 3 times a week or more so I get exercise. My mother was completely through menopause by the age of 49. This is depressing. I'm divorced for 5 years and started dating at that time but since then have not due to the way I feel about my weight. I'd like to hear from other women around my age and/or has been in menopause to know if the weight gain, hot flashes, etc. are regular.