Dear Sharon thank you for writing and I can not express enough how sorry I am you lost your son. It is time now Sharon to reconnect with your boy in a new way, in a way that is just as real and meaningful as in physical life. Your son is very much alive and around you, that is my solemn promise to you as a parent myself and as a medium.
If you had known what was going to happen to your son, you would have chose to have been with him at that moment, please let that be enough. Intent is everything and so is love. You were not meant to be there, so let the guilt you feel slide off like a heavy wet coat that you have no use for.
The signs your son will and does leave you can be many things… one thing for sure is if it is a sign it will also provide you with a personal feeling that resonates deep inside you and you must trust that he is communicating with you. As for the relationship you shared with your son, there is no doubt in my mind that despite the underlying issues, that your relationship was filled with love and IT IS NEVER TOO LATE TO MAKE IT RIGHT.
You can choose to have a relationship with your son still or not. It is not a pipe dream to believe you can talk to your son, nor are you kidding yourself about it if you choose to connect with him. Believe, talk and include him in all that you do, he has not left you, he simply has changed forms. Who he was, his personality, his likes and dislikes, everything but flesh and blood is still alive, consciously aware of life and more aware than ever before.
So Sharon find comfort in anyway you can and find your truth no matter what that is and remember guilt can not live where love does. Take care and I wish you well.