I feel like a horrible person for feeling this way, but here goes. I have a friend who I've known for over 15 years, since we were at school together. She found it difficult to make friends at school and has had quite a difficult home life which led to a series of emotional and psychological issues. She's a lovely, warm person, but throughout the years we've been friends I've felt drained by her company as she is often in a state of emotional distress and wants me to listen to all of her problems. She's had a fair few fallings out with friends over the years and I guess me and one other friend from school have been a constant for her in some ways. I've never discussed it with her but I'm fairly sure our other friend also finds her quite draining to be around. I feel awful because she seems to think we are this really close unbreakable trio but I find myself actively trying to 'ration' the time I give her. I live in an overseas country and she'll look up what time it is where I am and ask if I'm free, or bombard me with calls on WhatsApp. I've tried to say that I'm not available most times she wants to talk but she doesn't seem to get the hint and just keeps messaging me at different times, asking if I'm on my lunch break or when I'm waking up in the morning.
I don't want to cut her off or anything like that - she is a nice person and I know she really values our friendship, which makes it difficult. It's just hard to be friends with someone who is so needy and it feels like I'm more of a counsellor than a friend most of the time. How do I distance myself without hurting her feelings? She is quite fragile emotionally and I feel a sense of duty towards her, but it does feel like a chore. I don't mind texting every so often, even a few times a week, but I'm not keen on long phone calls which I know is what she wants, and when I move back home she'll get upset if I don't spend time with her regularly too.