Yes, that swing from intense shame to a sense of no shame can happen in high-dose truffle ceremonies. Strong experiences often loosen habitual self-judgment for a while, which can reveal both the weight of shame and what it feels like when it drops away.
For some, moving between these poles helps them notice core beliefs and recalibrate after the session. Outcomes vary, and I cannot verify what it will do for any one person, but many people report that this contrast becomes useful material for integration.
It can help to set a clear intention, have trustworthy support, and tend to integration afterward with journaling, gentle embodiment practices, or a talk with someone experienced. You might also find this short Q&A on shame in truffle ceremonies helpful: this discussion about shame and a truffle ceremony.
Wishing you a grounded integration.