Loved your story. I was adopted my older parents, they were 43 when they took me on back in 1971. It was a mixed bag for me. That said, one thing I did appreciate, or come to appreciate was the wisdom that came with their age. I learned a lot from them.
You've got this. Your son will remember the love, not the age. All we can do, young or old as moms is our best and that's what you're doing.