Heartbroken for DD - best friend leaving school, again!!!

[Onesmallnoserighthere]

My poor DD7 found out today that her best friend is moving to another town. She's a very sensitive girl and while she does have a lot of friends, she gets on best when she has a best friend she can hang on to. Her other friends all have a best friend of their own and I know that when her own best friend is off sick, she often ends up alone at playtime.
What makes it really sad though is that it's not the first time this has happened. In reception she had a joined-at-the-hip best friend, but he developed severe anxiety about going in to school and stopped attending at the start of year 1. She took a while to adapt, going through a phase of running off and disappearing in the school building or pretending to be ill at playtime. Eventually though she branched out into other friendships and is very close with her current best friend.
She was crying this evening, saying she loses all her best friends. She said that she doesn't think she wants another best friend, in case they leave. I said to her that when her other best friend left, she picked herself up and made new friends and everything was okay again in the end. And she said "I don't think I can pick myself up twice" 😥 It makes me so sad that she has to do it all again!
How can I help her? I've been worried about her lately because she seems like she's developing some signs of anxiety. She read on a poster that air pollution kills however many children a year, and after that she spent a week telling me and her teacher and the school nurse that she's struggling to breathe. Also asks me about every little pain and mark on her body. The loss of her first best friend coincided with becoming a big sister as well and a year on we are definitely struggling with giving her the attention she needs, and now I'm going back to work I'm just being stretched thinner and thinner.

You can help her by explaining these things happen, it’s perfectly normal. She’ll miss her pal, but of course life goes on and she’ll have other friends.

Her language re picking herself up seems strangely adult. Make sure you’re being matter of fact and upbeat yourself. She’ll be fine, and to be blunt have to cope with worse than this throughout life. Help her now, and she’ll cope in the future.

I totally understand, my DS also went through this twice but both times the families emigrated.

Do the school do anything to help DC with nobody to play with at break time? Our Primary used to have a friendship bench and activities they could join in on certain days.

It might be worth talking to her Teacher and seeing if the school can encourage another friendship or activity.

Does she have any friends out of school?

And what do you do so far to help get with her anxiety?

@BunnyRuddington they have a buddy bench but she's told me nobody comes when she sits there. Which is odd because I thought they had "buddy" volunteer older kids who are supposed to come. I find it strange that she says she's alone when her best friend isn't around since she definitely has other friends. Maybe she just doesn't know how to approach them at playtime. We do have parents evening coming up so I can talk to her teacher. Her year 1 teacher was helpful about finding other children to pair her with.
The headteacher spoke to us at pick up time today, he asked her how her breathing was doing and said he'd helped her with some breathing exercises earlier in the day. This was probably a reaction to the bad news because she hasn't complained about her breathing for the last few weeks. Honestly I don't know how to help her anxiety. I have health anxiety myself so I am absolutely modelling that behaviour.