You are not alone. I am going through this myself. Sometimes it comes with anxiety attacks (as of right at this moment of writing).
I am a 30 years old, entrepreneur. I made some not so smart moves. I failed at my last startup and lost almost everything, debt collectors breathing on my neck, I have a son. It affected my love life, my personal life and my professional life. It has taken a toll on me. I used to take pills proscribed by my psychiatrist. Not anymore. I decided to deal with it without pills.
Whatever you are doing, do not stop dreaming. You cannot stop. I never thought I would be looking for a job after 6 years of independent work. I know it might sound stupid but I thought working for someone else meant failure. Blatant failure. I thought I lost my dreams, my aspirations and my internal drive to succeed. It was hard to assimilate, it still is today.
I live alone, I consider myself very level headed, and driven but this situation took a heavy told on my emotional self. Lost all my drive, thought of dying (the feat of dying triggered bad anxiety episodes). I own a gun (this made it more stressful).
This is what I did: 1. I gave my gun away to my mother. Told her to keep it. This took a heavy stress out of my head.
Took time to do nothing. This was by far the most difficult thing to do. As an entrepreneur "to do nothing" is never an option in fact I have had to always try 10 times harder to make it.
I tried to develop an interest that was different from what I used to do. Something not work related. I chose to watch old movies (1930s-1960s) and analyze them for appreciation. I have watched many now: Citizen Kane, the wizzard of oz of 1939, seven warriors, and few others. This has helped me immensely to distract myself and even uplift my emotional thoughts.
I started to accept and embrace change. I realized something I had lost long time ago: "struggle is what made me the person Ia today". I have to embrace this moment not fight it. Do not let this uncertain phase of my life drive me under a rock. I have had some fairly challenging phases before and came out victorious. Why keep pounding myself for something I perceived as a blatant failure? I had become used to succeed, being comfortable made me forget how difficult was for me to get here. Rock bottom is rock bottom, there is no way you can o any deeper. I realized that. All it took was a change of perspective. I gave myself a chance to fail before it was never an option. I was fair to myself failure would and always will be there waiting for me given the choices and risks I was taking! so why would I give up if an always present risk was real now? It is time for me to change strategy.
Get a job. It is not hard to get a job when your expectations and moral is low. What was hard though was to get a job I liked and enjoyed. I applied to many many jobs. I finally did get a job offer. I think I will enjoy this one and I will actually can learn many things from. It will help me take a break from this entrepreneurial life I used to cherish. It is a fresh air for me. Its time to get back to the drawing board. I start this job this coming monday. I am nervous, last time I had a boss was 6 years ago. I feel little low and do not know if I can succeed so I read my CV and I realize I have done so many awesome things! All this amazing things and experiences would have never been possible if I had not failed. Maybe I will give myself a chance again.
Don't give up on yourself. We can talk more if you want.