Embrace what you have now
Everyone is busy. People say that they are going to contact you, then get occupied with other things, and don’t. People who you thought were your friends are missing in action. Try not to take it personally. The fact that people have moved on may just mean that it is time for them to move on. This may have nothing to do with you. It does not make either you or them bad people. Be grateful for what you once had, and move on and embrace what you have now.