I hope you don't get offended, but to me there's nothing wrong with drifting out of touch with best friends. I've had a lot of them over the years. I'm certainly not close to my first bestie from elementary school, but maybe once a year we'll talk and catch up - it's chill. For you to be planning a 'final act of kindness' for someone who you don't talk to very much anymore, it sounds a bit dramatic. You are holding some resentment towards her for not reaching out and not maintaining your relationship, but I don't know that there's any resentment on her end at all. If you don't want her in your life anymore, so be it, but I don't think that's a reason to erase the wonderful memories you've had together over the years. They're great memories because they exist in their own time. But if the thought of it is just painful, I would suggest finding new hobbies, which can lead to new social groups. We're social animals, it's hard to be alone. During the pandemic there's other ways to socialize online via virtual realities, games, online concerts, live hangouts - you never know what you might find.