Nothingness cannot be grasped by the mind, emotions or somatic sensations. Your attempt is trapped in dualistic thinking to which we humans cannot escape at this conjuncture in the cycle of time.

I only know of one ritual that attempts to explore "nothingness" or the void - that is an indigenous shaman practice.

I wrote a piece on it "Void": https://medium.com/know-thyself-heal-thyself/void-9399fd9f5dbf?sk=fdd67dd7f89fcf009f5420681168e696