what am i to do?

Before I go any further, I just want to share with you my story of how we came to be interested in adopting. We first started off as foster parents. Then went on to be Professional Parents. One day, my sister in-law showed up at our front door. She and her 4 kids showed up for the weekend. Then on Sunday, she asked me if we would take baby in. Keep in mind that this child is a child outside of her marriage. Instantly, I said "yes!" We had baby for almost 6 months and what we thought was a just a visit with them turned out to be something totally wrong. I had a feeling about this one visit. When we went to get him, she didn't pick up her phone. We showed up at her door and she didn't want to come downstairs. To make a long, sad story short. She then changed her mind about going through with the adoption. My heart broke into a million pieces! I didn't know what to do. I fell to my knees and begged that she think twice and if she didn't want to go through with the whole process, if she would consider an open adoption. Where she would be totally involved in babys life. She didn't give in. I left her home in tears...The bond I had with this child was priceless. Today we are still very much involved with baby and I know that he knows we are both there for him. Part of me wants to continue pampering this child as if he were mines, and the other half is saying that I just leave things as it is and wait for my own children. But how can I? I gave this child all that I have and still do. I still consider him my own and continue to pamper him as if he was mines. He is now 13 1/2 month. Am I wrong that I am doing this? Please help!