Anyone have 4 kids ?

So I have 3 kids ages 4, 3 ,and 2 .

And I want 4 so I want to have my last one already, but I do suffer from anxiety so Idk if it's a good idea ,

So if anyone that has 4 kids was it hard to adjust from 3 to 4 or how hard was everything , I tend to get bad pregnancy symptoms too so was being pregnant with 3 hard ?