Hi dangermousetheory

There isn't much 'you' can do. Letting go will happen when it is ready. Keep journeying and you will be rewarded.
The fear seems to come from the lifting of the veil, so to speak. When your ego starts to exit stage right and everything you held as true in your life no longer applies of course the minds natural reaction is one of 'holy shit'. The more you can embrace this, the better IMO - it leads to some incredible places.
One key is to know, in your core, that everything will be OK. Always.
Meditation before helps. I like to listen to satsangs or talks from spiritual teachers.
I personally find it easier to let go if I lie down rather than sitting up.
Also try smoking several times in one session. I find it easier to let go on the second or third trip.
With regard to dosages, do what you feel will be right. I smoke ~30mg in one hit in a vapour genie and hold it as long as possible.
Have fun!
Much Love <3 xx