I feel like that a lot of times. Sounds like a midlife crisis. But really, you didn’t waste it if you learned something from it and got stronger because whatever doesn’t kill you makes you stronger.
I have pretty bad anxiety and occasionally get panic attacks so I feel ya. Life just sucks as you get older. Best time of your life is when you’re young and carefree and just ignorant of everything and hopeful & positive about what life will bring you, not knowing the real world. Ignorance is bliss. If you enjoyed your youth, you did not waste your life. Being an adult sucks so do not worry, we are all in the same boat. I am just scared of death now and what ceasing to exist will be and if there is an afterlife and what happens after death. I have given up on life and just live the minimal things that give me happiness and go with the flow. I just hope there’s some meaning to this at the end, that is all.