So sorry to hear your son is estranged. Praying he comes around. My oldest son is bipolar, and when he went off his meds would be mad at everyone. He once went almost two years without speaking to me, but I continued to send him messages and cards. He finally got back on his meds and started talking to me as though nothing had happened. I’m telling you because I know how much things like that hurt.
My brother and sister have no contact with me due to a conflict over my parents estate when I forced them to sell a cabin. As a co-owner they had the option of buying me out or I could force a sale, which I did. Unfortunately , for them, the law was on my side.