Singer, I don't want to rain on your parade, but once you're over 35 you are in fact peri menopausal. Being peri menopausal increases any maternal desire you have, as your hormones drive you to have another baby. It will have passed off in a year or two.
Maybe try and connect with your little boy some more and find some groups and classes for him, if you feel the problem is that he's lonely.
By all means have another baby, if that's what you want, but your advanced age, and declining egg quality, plus the fact you are far away from family support, even if you have a healthy baby, make me cautious on your behalf, hence my suggestion you get a dog for your boy.
Good luck with it all- in my experience the ttc journey is paved with all kingpins of stones- and I hope you achieve your dreams without stubbing your toes.
You are not indeed the only one in this situation. Lots of women have made the difficult decision not to have any more children at this advanced age, me included, except I decided not to ttc again in my late 30s.
It's not an easy decision, and believe me getting a dog or cat helps more than you might think now.
Anyhow, good luck!