He doesn't get it...

My husband and I are in the process of stepparent adoption. I have been mommy to his son for the last two years and we are making it official. Bmom has signed the consent/waiver and we are just waiting for my FBI background check to come back. Some back story: J was with his bmom until just before his 3rd birthday. My husband was repeatedly denied visitation with J and denied access to his medical records (he was premature and there was some question about possible genetic disorders). In March of 2011 my husband started getting regular visitation with J every weekend. When J would be returned to his bmom he would cry and scream and be completely inconsolable. In May 2011 J mimicked smoking a bong (or so we thought) and we had his hair drug tested and his results came back as a moderate meth user (3 weeks before his 3rd birthday). Husband was granted emergency temp full custody the following week and J has never been back in his bmom custody since. Custody orders granting sole legal and physical custody of J to my husband were finalized 10/19/11. Bmom was allowed supervised visits through CASA, but after final orders said "what's the point" when asked by my husband if he should plan to still bring J for visits. She was arrested 11/06/11 for felony drug charges and subsequently pled guilty to possession with intent of methamphetamine. She was in jail for 6 weeks, no contact with J (obviously). She made one phone call Christmas day, one call in Jan, one on Easter (2 minutes and he had no idea who she was), and then one this last week before she signed the consent to my adoption. Bmom said she wanted to relinquish parental rights when she received the wage withholding at her place of employment. J also maintains regular skype and phone calls with bmom's parents and we have no intention of "cutting" off that part of his family. I am terrified that she will revoke her consent or make it so we have to try and get her rights terminated. My husband says I am J's mother, but legally I am not. He needed an MRI (to ensure there was no damage to his spine and brain from her drug use), I couldn't sign the medical paperwork. When the dr asked if we were the parents, DH said "yes" but when it was explained why we were getting the MRI, the Dr looked at me and said "so you're just stepmom". It was a punch to the gut. For two years I have been mommy to this little boy. I have helped go through withdrawals, tucked him into bed, taken him to his physical, occupational, speech, and behavioral therapy. I want to be legally recognized as his mother. My husband doesn't get my fear or stress. He IS dad and while I mom to this little boy who grew in my heart but not my belly...there are so many who don't see me as his mom. I know he tries to understand and he always listens me vent and worry, but...I don't know. Has anyone else experienced this? This overwhelming fear of never legally being mommy (or daddy) and your husband not really understanding where you are coming from because he has the security of knowing he is biologically and legally dad? Fingers crossed that in just a little over a month this will all just be a thing of the past...