Through my teens and early 20's, I was always in good shape and weighed about the same. I was about 5'4 and weighed from 115-118lbs. Even after I had my first 2 kids I would quickly lose the weight and be back down my normal size. I had my 3rd child when I was 25 and I really gained a lot during my pregnancy. My marriage was far from a happy one (the pregnancy was unplanned) and I found solace in food. So after giving birth I was about 160lbs and unlike the other times, I made little effort to lose the weight. My husband didn't seem to care, not because he loved me but because he hardly new I existed anymore. I had very little desire to have sex and hardly ever even masturbated. I was like this for a couple of years. My marriage got worse and worse and I just didn't care what I looked like. Then one day one of my neighbors who was also in a bad marriage told me she was contemplating divorce. She wanted to get in better shape since she might soon be single again so she begged me to join a gym with her. I really didn't want to but I did for her sake. Well after a few weeks I felt alive again. I began to lose weight and eat better and after 6 months I lost almost 30lbs. I felt great, began to notice men (and women) looking at me again. And I loved working out. I started dressing sexier again and felt like I mattered. After a year of hard work and diet I was back to 115lbs and I have been there for ever since. This gave me the confidence to get out of my marriage and start a who new life. And my sex life just kept getting better and better.
Losing weight has to be something YOU want for YOU!! If you are happy with what you weigh, no matter how fat or skinny OTHERS may think you are, then that is fine. Other than health reasons, It has to be for YOU!
As far as being sexy, in my opinion Sexy is all about attitude, not appearance, There are some incredibly beautiful women who are just NOT sexy. And some who most would consider overweight who are very sexy!
Do it for YOU!!
Just my long winded two cents.