So don't take money from those people. I'm not trying to be facile here. I'm asking you to recognize that if failing to provide a return to a startup investor generates acute non-dischargeable guilt, that is probably a good sign that you rationalized away the arguments for not taking money from them in the first place. If you're a pro, you do the company thing with the clear and honest expectation that you are likely to fail.
Companies going public spell this out in detail in their disclosures, which practically shout "do not put money into this". And those companies almost invariably have cracked 9 figures of revenue!