estranged son will be 33 on the 28th

So many years have gone by. I have lost both parents and a beloved partner since.
My son was not available. I was surprised since he loved grandparents growing up. He changed to a different personality as a teen and that person seems lost.
I have not been privy to his life for many years and about now as his 33 birthday approaches I am not sure if I will feel that good to be ignored one more time as I think of acknowledgiacknowledging the birthday.  I have changed.
I have always been afraid I would regret ignoring the day. I just am not sure anymore. I am so dryer up as a mother with him.  I know I care I know I love him but enough already the little stinker leaves me cold.
 
What to do what to send a Stupid again and be ignored. I hope I will be well buffered and not suffer aas it comes and goes again.