Birth after death of a child?

It has been a little over a year since my oldest child passed away. He would've been twelve this year. Our family went through a great deal of suffering during his illness. Becoming pregnant was the last thing I ever expected to occur. My children are many years apart due to past conception issues. Anyhow, this pregnancy has been terrible in many aspects. I'm concerned about bringing a new life into the world after the grief I continue to experience. I also feel guilty about having another boy. People ask insensitive questions, specifically, if I believe this child is reincarnated. I consider myself a person of Faith. So, I don't ponder about why things happen/Ed. I simply focus on the future and present. But, I am finding it difficult to accept the future. 
To complicate matters, my work hours have increased, I totaled my vehicle and medical bills from my son have depleted my funds. Even if I find a way to manage/cope, something else exacerbates overwhelming feelings. 
I have a five year old who has very vivid memories of the part three years and is vocal about them. She also retells her brother's passing. 
 Has anyone else experienced anything similar? If so, how did you manage or grow into a new normal with a new child who does not/will not know of the love  returned to the Lord?