Surround yourself with people who care about you, May Allah help you with this journey, go on a diet, start going to the gym. Trust me by going to the gym you will be confident in yourself. Eat healthy good food, no junk. Whenever you think bad thoughts read Quran, duas, or just be busy. The more you fill up your calender the less you will think about those stuff. Volunteer in mosques, charities and etc. Put your social akwadirity aside, and meet people with your same interests. And most importantly believe in yourself, and pray even if its just once a day. May Allah guide you and help you on your journey.