Feel disconnected from everything and everyone

Am I the only one feeling completely disconnected and distant from everything and everyone, post-treatment? I see life events around me and it's like I'm peering through back-to-front binoculars. Everything seems far away, like it's nothing to do with me anymore. It's like I've already gone. I miss life's highs, excitement, dopamine rushes. I feel like wherever I am, I'm not really there. I wear my smiles on the outside so I don't look miserable. It's like I'm waiting to go any day, even though I am post-treatment (although my cancer is chronic though, they can't get rid if it). Urgh.