How to mend a broken relationship with my 42 yr. old son?

I am the mother of the 42 yr. old son whom I described as verbally abusive Jan. 14, 2012. My son has not apologized or called after yelling at me, showing no respect for me as his mother. I feel the need everyday to talk to him to let him know he hurt me so much with his lack of respect shown with anger. I made an appointment with a professional and it was the best thing to do. People who are passive are easy targets for verbal abuse. He learned by examples of his father's behavior. Every time the phone rings, I hope it will be my son calling. I pray that one day soon that he will realize what kind of a mother he has ignored. I will always love him and want the best for him. I wish I had the answer for his anger and lack of respect. He is not happy because he is always attempting to try different challenges. It's like he is competitive and seeking attention. I am not calling him because he is the one who verbally abused me. My husband and I have a beautiful home admired by others. I am surprised that he only visits 3 times a year. He is missing so much. He lives 15 minutes away. I was wondering should I write him a letter? If I did, it would be soaked with tears. I will be seeing my doctor again soon and he tells me my son needs help. It seems as though the people who need help the most are those sho seek help the last. What suggestions do you have to mend a relationship which hasn't been the best.