Hello I’m a female who has been battling with my weight for over 20 years now?

Ok I went to the doctor today to get a thyroid test because I believe I may have thyroid gland.Over the last past year I have been noticing my hips and stomach to have gotten bigger. So I researched it on why was I gaining so much weight even when I have been dieting and exercising. The symptoms I have been having are weight gain, foggy head, forgetfulness, nails breaking and tiredness. I told my doctor all of this and he said he would do a test but he doesn’t think I have thyroid problems. Why when I’m having all the symptoms and unexplained weight he really made me to feel bad. So has anyone ever had these issues and if so what was it? Oh yeah he told me that my test results would be back til later.