Having a second child...

I have a 19 month old boy. The plan has always been to have two kids. I got pregnant pretty easily the first time, so I’m luckily not terribly concerned about the logistics of getting pregnant. My tentative plan was to start trying around the time he turns two in the spring. Well, that’s coming up in like four months. I still have my IUD and I can’t bring myself to get it taken out. I love my son but he is so much work. I would qualify him as a difficult child. He still doesn’t sleep. He is a huge mamas boy. He’s smart and funny and loving and a lot of great things as well, but, like most moms, I barely have a minute to myself. I was thinking last night “maybe it’s just supposed to be the three of us.” I know I want him to have a sibling and he loves other kids so much, but I’m just really struggling with the idea of exponentially increasing the amount of work that would come with a second child. Anyone been here?! Or here now?! Decide to just have the one? Decide to have the second and how did it go? Also, we’re 35, so we can wait maybe another year, but I don’t really want to push my luck or be getting pregnant close to 40. I know many people do, it’s just not really what I’m looking for. I appreciate your thoughts!