It sounds like textbook depression and/or anxiety, which yes you need to get diagnosed by a professional.
You’re not “blaming” your current situation on depression, but depression could be an explanation for why you feel the way you feel and why you haven’t just “snapped out of it/manned up” and become the high functioning, successful person you have the potential and support to be. You’re not an ungrateful person who is throwing away your opportunities, you’re a person with a problem that needs addressing.
There is treatment for mental health problems and it consists of a lot of different things, from self guided meditation to medication to talk therapy, and all have their benefits and shortcomings.