Although you say you accepted the loss 35 years ago, you continue to feel guilt about the lack of connection and anticipate renewed grief when your mother actually dies. This suggests to me that you are suffering from what is called “incomplete mourning.” Because the loss was from abandonment, not death, it may be that you didn’t get the support you needed at the time. You couldn’t quite move on all the way because you didn’t have the finality of death. Instead you were left with some flicker of hope that you’d finally get the mother you longed for and deserved.
You lost your mother in a very real way when you were only 18 and launching into adulthood. Research tends to overlook young adults who lose their moms, according to Taranjit (Tara) K. Bhatia, PsyD, a clinical psychologist who specializes in relationships, including mother-daughter bonds. Because they’re already adults, people assume these daughters don’t need maternal guidance. However, losing a mom has a powerful effect on young adult daughters. I imagine that you were angry, confused and sad. You might have even worried that you had done something wrong to cause it. You had a mother who was alive in the world who wasn’t really alive for you.
Well-intended people are suggesting you call her, which seems to be triggering the incomplete mourning. Those people don’t know your history. They are basing their suggestion on an assumption of a healthier relationship than you have ever had. They don’t understand that sometimes personal emotional health depends on separating from a toxic parent.
I see no reason for you to change your level of contact with her. Holiday visits and an occasional call acknowledge her, but maintain an appropriate boundary. There is no reason to think that increasing contact will get you the mother you always wanted. She isn’t likely to change at this point. You are likely to only re-experience the wounds of being left.
Instead, focus on accepting the positive “mothering” that comes from your friends and others who love you. Positive adult friendships include the nurturing and loving elements of mothering without the craziness your bio mother offers.
As for the people who are trying to give you advice: Thank them courteously for their concern and go your own way. They aren’t likely to understand your choice so there is no point in arguing with them. You don’t owe them an explanation. You certainly don’t need to follow their bad advice. Spend your time and energy with the people who count.
If you continue to be distressed, I encourage you to see a counselor to help you finish grieving the biological mother and to find the mothering you need in others.
I wish you well.