Treated as pariah by family (grown children 28.30)?

Neither of my grown children care about me. My son took all the money my family left us 2 years ago and have not heard from him since. Daughter is loyal to her father and will not reveal anything to me- leading me to worry son was dead. Ex would not call son when son had potentially fatal disease in hospital. I was there for both of my kids growing up- in fact- I doted on them. How can people be so cruel? My daughter did not bother to call me when my parents died, either.