Moms of 3+, can i ask...

I currently have 2 kids. A 5 yr old(best surprise ever) and a 7mo(planned). We always talked about having a big family but I feel so torn now. We both have adhd so keeping up with housework is more of a task for us than most. I'd love to have at least one more but im genuinely scared for how big of a change being "outnumbered" would be, especially since now we are easily able to split out time so each kiddo gets enough attention and time with us. Moms of 3+, what was the hardest change from 2 to 3? What are some important things we should really factor in that we may be forgetting to think about? Please any advice is welcome. I would just love to hear other peoples points of view to get a more realistic idea of life withe more than 2 kids.