AITAH for cutting my bestfriend off

I recently decided to stop talking to my best friend whom i work with (call her B), i've known her for 4 years now and we were the best of friends. We used to hang out all the time together going to bars and pubs etc.

However for the past year or so her attitude towards me became very different, she started making fun of how I dressed even when my other friends say different about what im wearing or how I had my hair cut saying i look stupid. And she kept making fun of my age (I'm 29 she's mid 20s) calling me an old man due to me having a bad knee periodically.

recently a few months ago a new manager was transfered from another of our franchise to our store (call her c). Admittedly we became fast friends with this new girl and we started to include her in our weekly nights out and stuff. Until one day I fell out with her because she was constantly cancelling plans at the last minute or worse not even telling me that she was cancelling. So we fell out and now don't speak unless its for work purposes.

As soon as this happened I found that my invitations to nights out or other activities were basically nonexistent unless I organised something with (B) but more often than not we'll plan to do something only for her to never follow through and I see on her stories that she went with (C) instead to the places we were going or activities we were planning on doing together.

All the while she constantly makes fun of me or berates me or puts me down when I tell her I want to try and do a new hobby. She even makes fun of me when I tell her when Ive met a girl I like.

So about 2 months ago I stopped replying to her messages and basically stopped talking to her unless its at work about the shift. I feel so much better and less insecure about myself but sometimes i feel guilty that i don't speak to her anymore.

AITAH?