Do your beliefs imply a Necessary being exists?

[Reforged]

Who says existence itself is necessary?

I don't know...?

If you can't prove existence itself is necessary how can you hope to prove a being must necessarily exist?
Without the assumption existence is necessary you can't make the claim a being can necessarily exist.
That'd be like me saying flight doesn't have to be necessary but someone necessarily needs to fly. Claiming the latter must assume the former.
Your entire line of reasoning depends on that assumption.