You have done a beautiful thing being there for this little life & passing him to a couple ready for his unique challenges. As agonizing as all this has been for you - I think it's cool you've found a parallel with the BM experience.
And NO ONE can judge your decision. I don't think any of us could guess what we would do until we were THERE. (But I will anyway I think I would likely do exactly what you have done & would be feeling the same way you are feeling. I applaud your strength & know that sweet baby is where God intended.