Our family gets along too, I don't know why you're trying to imply we don't? We're all far flung and have an annual cousins party at the lake. My 13 nieces and nephews aren't on facebook because it's for "the olds." Some of them have instagrams but they have multiple accounts and different "finstas" - candid fake accounts they only share with certain friends etc and delete and remake new accounts with friends etc constantly. They're also on TikTok lately but generally will text the funny ones not through the ap. We have a family group text and send photos. I send them snail mail bday cards with cash in them, sometimes they write back and sometimes they'll call and say thank you or text etc.
Group text is free too in case any of your family members have ethical reasons why they don't want to be on facebook or want to get off it to improve their mental health.
I'm sorry about your loneliness and isolation. I agree that Facebook is convenient and free but imo not worth the time sink. Cheers.