There’s a lot here. Dating someone you have a working relationship with is never easy. It sounds like you are mourning the loss of this relationship. Replaying the past events in your mind over and over is not productive it only keeps you stuck on what you could have, would have or should have done. At this point, it does not matter, because it is over. Stop tormenting yourself. Some of the most successful people in the world have overcome learning disabilities ADHD and many other challenges to become great at what they do. You have nothing to be ashamed of.
Everything happens for a reason. This guy is not “the one” for you, but you had to go through this experience to bring you closer to what your purpose is on this earth. At this time, I believe you should stay as far away from your ex and his circle as you can, unfriend him on Facebook and don’t share anything else about your personal life. If you run into him or his family, friends, be pleasant; keep conversation light and very brief. If you are feeling miserable, DO NOT let them know.
At this time, please pursue therapy to help you overcome your insecurities before dating anyone else. Seek out support groups for people facing your challenges. When you do starting dating again, please give it at least a year before you begin shacking up. Work on friendship first, if you are insecure about disclosing some of your most sensitive feelings with your new love interest, then you probably should not be dating him anyway. I wish you the best!