18 years friendship ruined?

I “used” to have two gfs whom we knew since secondary school time till recent year. Let’s name lady A and lady B. I’ve missed lady B birthday celebration for 2 consecutive years and she is very upset with me. I’ve apologised and explain the reasons to her. Verbally she seems to accept it but her whole attitude changes. And lady A seems to be influenced by lady B and A starts to change of attitude towards me. (Which made me upset with how B deal with things) Due to this reason I didn’t tell them I was pregnant that moment. It’s hard for me to tell them all of the sudden that ‘hey’ I’m preggy and due the past few months changes of their behaviour towards me. And only recently when I gave birth lady A eventually texted me. We had a conversation via text and she said that she is utterly disappointed that our years of relationship has been drifted apart and she wanted to end this friendship. Sadly when I replied her that how I felt n etc it seems that she doesn’t accept it hence no replied from her since then. I really do treasure the friendship with both of them but it’s seems that both of them had changes. What should I do to save this friendship back. Both had left our common group chat and it’s seems the end. It’s depressing and losing them seems like losing part of me. Or perhaps I should move on like they do?