Try an LSDMT combo. This can help. Your mind is primed and ready to go.
Focus on intent and challenging that which you fear. Focus on what you are sacred of and face it head on. Go into your fear. It will change into something else. Have confidence in yourself and know that you will be fine. When it is the most challenging is when you are learning the most. Focus. Intent.
The ego can be quieted. The ego is like a scared little kid. Comfort that kid. Go with the child into the darkness. Show the child that there are no monsters under the bed. Offer yourself this and you may be surprised at the courage that rushes in.
I have had pre-flight jitters and now when I am ready I am actually excited to go. I plan it now like going on a trip. When I had pre-flight anxiety I would always feel that fear disappear the moment I took a that final step and inhaled the first hit. It feels so good to push past a fear. Psychedelics are self-regulating. If you feel you need a break then take one. Nothing wrong with that.
There are a few threads on the nexus about fear and pre-flight anxiety. Use the search tab and you will find so interesting threads. Good luck to you!
"In the universe there is an immeasurable, indescribable force which shamans call intent, and absolutely everything that exists in the entire cosmos is attached to intent by a connecting link." ~Carlos Castaneda