How to work on myself now?

Hi, im 16m. I recently had a break up and im working on improving myself. I recognize a lot of insecurity in myself that I had left unhealed and it unfortunately blead into my actions and the relationship as a whole. I also feel like I lost myself and I don't know where to go from here. I have reflected and recognize what I did wrong, but I feel like I'm beating myself to much over it. However, I honestly don't feel a desire to change, which is awful. I know exactly where I need to change and how to, but that desire isn't there which scares me. I personally think it's depression or me losing myself. I'm usually a very compassionate person but my actions in the relationship said over wise. I also feel a lot of my insecurity comes from a p*** addiction that I've had for a while. Its to the point now that I can control it for a while, but when stressful seasons hit, it becomes a problem and it obviously disregulates a lot of myself. I feel very numb and out of it. I have no motivation nor desire for anything. I'm a very ambitious person but every project or thing I work on feels so stale and boring to me now. Please help me, I want to fix this now so when I'm an adult, I can be the best version of myself!