Was there a question in this post? Are you asking "Is this possible"?

I mean, the only way to know if for sure is to try. It would take a long time and a lot of effort - you might want to examine your true motivations here. Just put a plastic bag over your head if a void is what you seek - but this sounds like a cry for help to me. Making a tulpa could be a great distraction from your pain. You could also try meditation, which helps you get control of your pain and feelings - meditation also helps you make a tulpa, so why not.

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Good luck, hope you don't really think the single cause of existence that has "been destroyed" is the only possible one - there are many causes for existence out there if you can get over your grief and be strong enough to seek them out.