An alter missing someone they shouldn't.
About a year ago I had a bad falling out with someone I considered to be a lifelong friend. She was like my sister. My other half. It was devastating and I (host) still think about it everyday. She knew about my system and was supportive and willing to educate herself; as well as interact with multiple alters individually. Everyone adored her. Even the littles who had little to no interactions with her.
One alter however grew particularly close to her. He took friendship break-up harder than anyone else. Even myself. For months I thought he was dormant as I had little no communication with him. I knew the reason. I tried. I pried. I got silence. A few weeks ago I was able to communicate with him again after a small interaction with said old friend. For some context, my partner is related to her. So I see her dueing holidays and some events. For awhile she has been talking to be like nothing has happened after months of not looking me in the eyes. It is difficult but I manage as the one who holds the system together. A comment she made about an alter without much prompting created quite the stirring within my system. Triggering the supposed alter forward. Often in co-front as of recently.
After years of recovering him from a persecutor to a protector he has reverted. He blames me. Hates me. Insults me constantly. Often at night or when I am alone with my thoughts. The rest of my system including internal protectors and such do their best to keep me sane whilst managing this day to day. But it is becoming hard on my sanity. I try to tell him how horrible she treated in the end and after. All the things she said and did but to no avail he holds a deep grudge now.
Any advice on how I can get through to him? Or this entire situation in general. I want to be as civil as possible. I also want to add on that my system communication overall isn't the greatest. But I try everyday to do better. Help, even a little would be awesome.