I need motivation

Last year from 27th October I locked in and exercised and was in a calorie deficit for less then 2 months and ended up losing 8 kgs, although not a lot I definitely saw a difference. But after school ended at the end of the year I stopped exercising and dieting and what not. Now I’m trying to get back in that habit of exercising and dieting and I’m struggling, yesterday I went out and walked for half an hour on my block and my back was killing me due to the excess weight on my whole torso and my ankles were burning so bad. Last year when I exercised I did it on the treadmill and after did other workouts at home. I’m kind of venting but any advice would be appreciated, I just need to lock in again I’m sick and tired of the pain all this weight causes and I’m tired of feeling constant insecurity from my looks.