@Miguel fear isn’t all that helpful for self-immolation. When I try and recall what ‘my’ emotional state state was prior to self-immolation there was some trepidation sure, but as Richard said ‘its way beyond fear’. The imminence of my own death was so beyond it just took my breath away. Another thing to remember is there has to be a sufficient connection to pure intent, one foot has to be planted in actuality with another foot needing to join in a sense. Without that connection - which is rather like being in an EE but with a thrilly, destinal element - your ‘death’ is just another fever dream just like any thing else the self concocts. My advice to you is to focus on felicitousness and innocuousness, EE’s and PCE’s rather than thinking about self-immmolation. You seem to be putting the cart before the horse. The powerful fragrance of actuallity has to impel you, to evoke that desire in you to self-immolate. You can’t simply push or propel yourself to do it without this impelling. This will also diminish the fear.
I guess it would be good to talk about the psychosis also. It is unknown territory as no one with psychosis has as yet self-immolated - at least to my knowledge. Not that this is necessarily a barrier. The list of AF people reveals a number of ‘worlds firsts’ - myself included 
. You are the one most knowledgeable about your condition and can best assess how to manage it and how your practise affects it. My above advice to you should still be applicable. I bet I’m telling you stuff you already know, but just putting it out there