Totally understand how you feel. Tbh, I lost friends since I was pregnant with my first. I only hangout with family, friends of the same club or people around me that understand our situation.
How do I cope with the changes? I will tell myself everyone has different path in their life. We have different schedule of time too. Not everyone would understand marriage life with kids and without kids. I do drop text via DM or Whatsapp once awhile, however, that's entirely up to them to reply or not. As long as I know, I still treat you as friend and we have known each other for ages. We also have to know that no such things as busy in life. We can spare little bit of time to chat, call, video chat, etc. Even sometimes, impromptu session meet are always the best.
Now with 2 little kids, I am a SAHM and I fill my time with family, in law and if I have free time Ill plan with friends of the same club and bring my husband along. Do I get me time? Ill do that perhaps when they are in school. Atleast for coffee, tea or do house chores, shopping, Netflix, etc.
If you are looking for playdates, you can perhaps get to know groups that does this mummy/daddy club on Facebook. You can always make new friends. Hope this helps.