Also don't mean to bring syringes back into this but have you considered plugging? It involves an oral syringe, so it's not a needle. It will save your mucus membranes from being hammered with nasty pill powder.
I'm not sure of the safety on a long term scale but it seems, to me at least, to be much less harmful than any other ROA aside from oral and sublingual.
I don't mean to push it on you, if you're doing well with snorting then that's still a big step in the right direction.
Good luck, stay safe