BW,
first of all the answer to the technical question that I can answer - those embryoes will always be the same age as when they were collected. You can wait until you are 45 and technically still have as much chance of getting pg with them as you do today. We have 50 year olds in our ED group pg. with 25 year old eggs first go so don't let that stress you at all.
Easy for me to say but try not to worry about it yet. Enjoy your little boy. I know that when I had DD I would not have even thought about trying for a baby at 4 months. I only considered trying at 6 months as I was already 40. The biggest regret I have about my LTTC journey is the effort I put into trying for a baby, at the expense of enjoying my DD grow up.
Hormones are still playing havoc with your body. Give your body some time to rest and get your other health problems stable and perhaps learn what "stable" means for you post prenancy. And then you can make a better decision about the future.
Most of all am sending you some hugs ((((hugs))))