Start by liking yourself, especially if youre not happy with the way you look now. Its just looks, remind yourself, that you can change, take better care of yourself, and achieve a look that pleases you. Don’t change to be better accepted by others, change because you want to! According to girlshealth.org,
“Body image is affected by a lot of things, including messages you get from your friends, family, and the world around you. ... Sometimes, having body image issues or low self-esteem may lead to depression, eating disorders, or obesity.” 
As someone who has gone up and down with their weight in recent years … being thinner does not necessarily make you a happier person. Im much happier now overweight than I was when thinner, you have to have the right mindset whenever you choose to diet and exercise excessively to lose the weight, don’t beat yourself up over how you look, or you’ll never be happy no matter what size you are. As someone on meds, battling depression, and trying to lose weight and keep off the weight has been a grueling task, involving walking everyday. Its easy to give up in life, when it comes to dieting, and the sooner you lose the weight unhealthily cutting calories, if not meals from your diet, the quicker you gain all the weight back, the minute you start eating 3 meals a day again. According to shape.com:
“Any form of depression, no matter how mild, affects neurotransmitters that control mood, thinking, appetite, and behavior, making you more likely to eat poorly, skip exercise, and gain weight.” 
Set a schedule for yourself, and keep track of your exercise -I keep a log. Not only does that keep you motivated month to month, but you can easily track your progress, and figure out whats working for you and not working for you. Everyones body is different, some on meds respond better to exercise than others, I know that being on meds, means that I will have accept being a bigger size in life, and that its important to take my meds, whether I am able to lose the weight or not. I highly doubt that I will be able to lose 50lbs in a year, but its worth trying to, sometimes you have to set more realistic goals for yourself, in order to begin the process of achieving your ideal body type, set smaller goals, to achieve larger ones.