Big boned teen weight loss?

I'm a 17, almost 18 year old female who is interested in some real advice for healthy weight loss and lifestyles. I am 5 foot 3 inches tall and weigh about 143 lbs. I have always had a larger frame than other girls my age so I think I would be healthiest around a weight of 125 lbs. But I need advice on how to live a healthier life. I also do not want severely restrictive diets as I had an eating disorder and do not want to trigger a relapse, I know my limitations. I would just really appreciate some FUN exercise and healthy eating tips. Thank you so much!