She doesn’t sound like a friend at all, let alone a best one 🥴 Perhaps the silver lining in all this is that you have been shown who truly cares about you and who to cut out of your life. As for the nappies, do you have a partner/BD? Can they send you the money or pick some up for you? What about your parents/siblings, can they give you some money to tide you over?
Is it the money for them your struggling with or that you can't get out to get them? Obviously don't know who you are so can't see what area your from incase your local to anyone on here
Not sure where your at but have you tried Facebook free groups or monthly subscription for diapers or even cloth diapering… we all have been here before once in are maybe not with diapers but I have with formula