Insecure about Future Plans

I'm having trouble falling asleep because I'm constantly bothered by thoughts about the future. I'm currently in my third year of college and I still haven't made any plans for what comes after graduation. I also feel insecure about my skills and believe that I haven't really learned anything during my studies. I often consider myself one of the worst students in my course, and it feels like opportunities will never come my way once I graduate. It's disappointing because I'm fully aware of all these issues, yet I struggle to make any self-improvements. I know what my weaknesses are, but my bad habits and lack of motivation continue to hold me back. I feel extremely disappointed and anxious about it all. Just wanted to share my thoughts with you all.