Welcome to the forum!
First, let me say that, from your post, it is clear that you are an amazing person! You are obviously extremely caring and giving and I applaud you for your volunteer work.
My "empathic" pain is usually emotional, but sometimes physical. I have always been able to absorb the emotions of others around me. I do feel the physical pain of some, but like your friend, it's usually in the same place as the other person is feeling it.
I've found that certain personality types tend to "absorb" the physical and emotional pain of others. I'm not sure if your friend has a similar personality as you, but it would be interesting to know.
It sounds like you are doing all that you can to remain at peace, focusing on kindness and compassion. I hope you can find a way to separate yourself from it sometimes. I know that may be impossible, but perhaps through your meditation you can find a way.
Fibromyalgia since 2007