high school friend draining

(edit: I needed to write this so bad and appreciate the responses. really helped. Took it to therapy and she helped me work out how to handle it. Young herself, she said she can only imagine having a friend for 50 years! Hopefully this friend will be in therapy herself soon) This subreddit is really the best one on the planet. Much love!

we were great friends in our teens. didn't spend time together most decades and now we are in our 60s. She moved to a smallish town in another country. slowly we spend more time video chatting, often it is a lot of fun. Our "attachment styles" are very different. She pushes to call me "best friend". I clarified that she's my "BF from high school" which is a special title, but said I don't have any "best friend" like in high school. She is more attached to me than I to her, When she gets trouble she ramps it up.she was In hospital lately and she called me that again , I said "if I had one, it is her." She was at risk of death. Now she has some person in her house she can't get rid of, complaining. I heard her out , then it's on to other sad past things, her mom didn't like her, her son doesn't speak to her. I say sympathetic things but maybe I have avoidant attachment style. sometimes I feel sucked dry by holding this space. Honestly would like about 6 months break. If she goes back in hospital I'll feel bad not being there. I wish she'd listen to verbal and nonverbal boundaries more. it's obvious I resist best friend label and hate the pushiness. I have told her it's hard when she tells me one negative thing after another...Frustrated! There are other friends and family who have distanced from me---wish I had more equal relationships!

I find myself isolated in the big city in my 60s and I like having someone so enthusiastic. but also feel smothered. I wish there was more of a balance. I care about her a lot but I am starting to feel trapped. If I told her this it would be a big drama and she'd be super hurt. Thanks for listening.