47 years old, tubal ligation, negative HPT, why am I so late with cycle?

Hi I am 47 years old my had tubal ligation(cut burned banded) years ago.  I have been late as I ever been with my period. I've taken HPT, it was negative, no symptoms of pregnancy, I feel super, nothing strange going on with body as I've seen described in other topics. I've talked with Nurse at the Gyno office, she tells me don't be alarm its probably menopause starting especially since I've noticed slight changes in my cycle within the past 2 years. (No insurance to go get exam now).  I am so scared and stress, how do you not be stressed when you are my age, don't want anymore kids, I have a 27 & 29 and grandson.  The only thing that was strange a few weeks ago, well a month ago I started having really severe hot flashes, I attributed to the abcess tooth and thought I was just having bouts of fever. I only took a few antibiotics for this, and now I continue to use salt water all day to keep mouth rinse out.  What is the problem??? Help someone? and Tell me how do you calm down.  I don't have a weight issue, I exercise regularly like always, and I have a somewhat good diet.  I did load up on vitamin c, folic acid, b12, and bioten while tooth was healing.