Why are friendships hard

I'm feeling like my friends aren't really my friends. I'm feeling really down lately and reached out to a few friends, and noone replied. Reflecting back I realised it's ALWAYS me who initiates messages or a catch up. They never ask me. I enjoy the time I spend when with them but wonder what is wrong with me. I know they contact each other often. So why not me? I feel like I don't have any friends and feeling really alone. I have 3 beautiful kids and a wonderful partner.i just want friends who care about me. I don't understand.