Good-bye friend?

"I expect I only have 40 more good years on this planet. While I am grateful for your friendship over the years, at this stage in my life I realize that the time we spend together saps my very life energy. There are so many people and activities that DO feed my soul, that help me feel alive, and inspire me to be my best - every minute I spend with you is a minute I'm not feeding my soul. This makes me feel resentful that you don't seem to get that the lack of comments on your Facebook wall, the plans repeatedly made and then broken, the text messages not returned - these all mean this friendship needs to lay fallow for a while.  The fact that you don't get my efforts at gently letting you go - THAT also incenses me. And because you don't get the gentle signs, I need to be overt. I'm sorry but we're done."

Is it socially acceptable to say this? I don't think so.

I re-read this fantasy exhortation, and realize I am not a good friend. And I think I am not able to be a good friend to my friend because I'm not being a good friend to myself. I need to have a deeper reservoir of love to share with my friends. And to cultivate that deeper reservoir I need to be taking better care of my emotional needs. I need quiet, stillness, exercise, sufficient sleep, and a sense of work/life balance. 

And when I have filled my friendship reservoir, I know I want to spend my energy stores on the people who make my heart go pitter pat - my sisters, brother, nieces and nephews, my husband, my mother, and the handful of nearest and dearest with whom I connect most deeply not through Facebook, but through coffee, cocktails and conversation. 

Which leaves me with this question: How does one tell a friend one is no longer interested in being friends? 

Three of my friends quite literally exhaust me. I've read enough issues of Oprah's eponymous magazine to know I need to gently pull back. (And yes I've tried to reframe my attitude about the time I spend with these friends, tried enjoying their company in larger groups where their intensity might be diffused, and tried gently rebuffing their calls.) In spite of my best efforts, these friends persist in reaching out; one even became belligerent when I was non-responsive. 

Sigh. 

I need help. How would you handle this?