It's not a useless thread. These are your feelings. And they matter.
Many of us feel as if we've lost time. Myself included. I'm paying for a university degree that isn't being used in a career. And I've worked a few fairly meaningless jobs. They were meaningless to me at the time, anyway.
Your time "lost" or ill spent can and has made you who you are now. Your character is being forged by it. Hang in there, don't drink, and go on to do some of the things that hold meaning for you. Find what means something and do that. It's really all any of use can do at any point in time.