It really depends on where you live.
In Holland truffles are considered luxury food. This means that it can be delivered anywhere in the Dutch territory.
There are many companies that deliver truffles in micro-dosing quantities, but I never tried them to give a recommendation.
What usually my costumers does is buy 10 grams of fresh truffles and divide it into 10 parts.
By the time they are approaching their last dose the truffle is still good to consume.
I don't think your negative experience with Cannabis should define your relationship with all substances.
Cannabis is a spirit difficult to have as an ally and often this work to narrow one's relationship with marijuana comes with conscious training.
Psilocybe fungi is much more delicate and friendly.
Find yourself a place you feel extremely comfortable and with people you completely trust (or alone) and prepare the logistics so that you don't have to worry about nothing during the 4 hour journey.
Get a dose higher than a microdose, enough to feel the effects and gradually work your way up to a full psychedelic journey.
I think this is important for anyone interested in microdosing because I believe that the microdoser needs to understand the effects and benefits of a full psychedelic trip before they can benefit from microdoses.
Thanks so much for reading and commenting!
Have a good trip.