first off, welcome!
2nd,you are not dumb!
but what i think you truly are is quite sick, and this lil bit here says a LOT:
"At this point, whilst I really care a great deal about this guy - I'm crazy about him - I also know this is dangerous territory for me. I have strong tendency to need to help and heal and I have lost myself entirely in a narcissistic relationship in the past. I'm worried about my capacity to handle this and so ultimately think I will have to step away. I'm scared to do that now whilst there is no one else there fore him. "
reads like untreated codependency,being show it reads like youve jumped from trying to save one person tot he next.
which there IS a solution for.
im not sure what " I'm crazy about him " means here, but it reads like youre crazy as insane and not crazy as in love. it reads like youre completely wrapped up in trying to rescue someone( again?) that doesnt want to rescue themselves.
and possible to try and avoid your own issues?
youre worried about YOUR capacity to handle this- welp, imma thinkin if you look at the facts of the last 3 months( youre crazy in love after 3 months?) you dont have the capacity nor the ability to handle him nor is it your responsibility.
doesnt matter if theres an army there for an alcoholic or addict- until THEY want to get clean/sober, that army cant to squat except sink down with the alcoholic/addict.
even when an addict/alcoholic- like myself- wants to get clean/sober, the help is best to come from someone that has been in their shoes.
witch, its been 3 months. how much longer do you want to spend losing yourself? it reads like youve lost yourself quite bad here and you dont deserve it.
and TRYING to rescue someone doesnt appear to be helping find yourself. im thinkin theres the possibility that youre doing that to avoid underlying issues- ones that WONT go away no matter how hard you try to resue someone.
PLEASE take any and all advise given from these awesome people here and run with it. they have been in your shoes.
p.s.
if this is an adult, hes responsible for himself. NOTHING you do will help him.
and hes lived without you up until 3 months ago. what happens after is up to him and not your responsibility