“Best friend” not sure what to do

Literally have no idea where to post this!

Best friend dilemma - I shall name her Claire.

So me and Claire have been friends for 23 years, we were always together. Her work colleagues always knew who I was as we did everything together and longest we would go without seeing each other would be 2 days!!

Fast forward to a year ago....

She started a new job, met new people and I was happy she was able to enjoy work as she had friends there, but gradually we saw each other less and less and I accepted we were both busy (although it never stopped us before)

But I started seeing posts of her going out with her friend from work, Nights out, cocktails near my home, holidays, posts about being best friends and the best girl ever. I am not petty and I accept we have other friends but I once hung around with someone else and got abuse for it.

I was finally invited to ONE event, there was a dog remark to me from the new friend and Claire completely changed and was bossing me around making me feel stupid, I put my smile face on and just went with it.

I told Claire exactly how I felt, I spilt everything out she no longer told me things, she no longer come to me if she was upset, she no longer just randomly messaged me so I spoke with her and she said it’ll change. It’s already been 2 months again since I last saw her, she has seen her new friend every day 🤷🏼‍♀️🤷🏼‍♀️

There was recently a birthday surprise for her friend with gifts and drinks, I barely managed to get a happy birthday on Facebook lol I think I have realised 23 years I may have just been a convenient friend and now she has met people she is more suited to I’m casted aside.

I do feel like our friendship is over, but it’s not like a breakup lol do I just continue as we are until there is nothing or just stop he bullshit now where she will post every now and then and pretend she gives a shit???

I’m not jealous, I was happy to all be friends it is the way she changes when she is around her.

Sorry for the long post