I'm sorry to hear that you feel like you've let people down. That's a terrible way to feel and live your life. Investors and advisors back you early on because they believe in you. Embracing that philosophy is liberating, and actually, allows you to take more risks and become more success (and happy) from my experience.
I'm sure they'll be supportive of your next venture.
Thank you for sharing your experience with everyone. I'm sure this wasn't an easy blog post to write.