Lost friends since being a mum

You aren't overreacting. I'm 36, had my LO almost 9 months ago. My oldest and best friend, known each other since I was 18, never once checked in on me (visit/call/text) when I was pregnant. O she congratulated me on FB when I announced I was pregnant and when I had given birth. But she's never seen her. Never asked how I am. So snip snip, off she can f**k. I am going to meet up with her and find out what the issue is, I need closure.
Message them, and ask them to come over, either together or individually so you can talk and tell them how you feel and find out why.

I’m still in touch with my friends who have kids, but I've drifted apart from those who don't. I guess it’s because our lifestyles are so different now, but it still makes me sad. I think that’s why people try to make new 'mom friends' who can really relate.

This is hard. It's such a shame to drift apart. Have you messaged them to ask how they are and what they're up to? Could you invite them round for a cuppa/ picnic in a park/ coffee/ walk etc. It is difficult when your life has changed so much, and until you go through motherhood yourself I don't think others can truly relate or know how isolating it can be.

Not overreacting at all. This happened to me firstly when I "settled down" with my now husband and moved 30 min drive from my hometown and secondly when I had a baby. People move on when their life paths vary widely to one and other. It is absolutely pants, and I really feel for you, my BFF ghosted me 5 years ago for no reason at all and it still hurts so much. Mainly I suppose because it's so difficult to make friends as an adult nevermind as a mum. I've been to every mum club going and no one was interested, understandably because they may be in their bubble or not need new friends. It's really daunting but try out yourself out there to make new friends xx

Your lifestyle is so different to the ones they are living that this often happens.

This is normal unfortunately I have my best friend who we still are best friends even though she has no kids. I find it really hard to make mum friends as I'm quite regular with contact etc but most mums are obviously caught up in mum life/their own life and bubble that it's almost impossible to meet up or stay connected anymore. It's lonely out there so I feel you.