I totally agree with PALady! You did NOT plan your pregnancy it happened and I am a true believer that everything happens for a reason! Focus on the end result, you have been blessed with a gift from God, your son is healthy and sounds like an ANGEL to me! Some day when he is older you can share with him the surprise of him at a time when you were suffering pain and how he changed your life for the better! Yes, what he endured was awful but you have given him a wonderful life and he you!!
Forgiving ourselves is indeed a task but once done, everything around you will look different. What if your son hadn't been born?
Start being grateful for every experience you share with him. Sounds corny, but being grateful for all of our good, does over power the bad thoughts and memories! Writing my thoughts in a journal is like therapy for me, once I have written my feelings it starts the process of letting it go! You could write him a letter (but not give it to him) and tell him everything....save it and re read it or write it and burn it, just some ideas to ponder.
I for one think you are a wonderful Mother and person, you deserve to be free of this undeserved burden of guilt! You are in my thoughts and prayers!!