Osem your posts about both your sons screams out just how much you love them and trust me this can be clearly seen by all.
I can only imagine the heart break at having to make such a difficult decision and it must be a catch 22. What do you for the best do you wait until you can no longer care for your son in where Osem Jnr #2 could be emotionally traumatised by losing everything at once and all that is familiar to him without you being there to offer your continued support, or do you do accept what is best for all.
Osem don't beat yourself up about this as you can still give emotional support.
Everyone concerned in Osem Jnr #2 life needs the peace of mind that he will be settled and content in full time care and I think you have made a very difficult decision out of love for your son.
Take care