Please don't be distressed. It's an excellent age gap IME. They both still nap in the afternoons, and dc1 gets 1 to 1 time during dc2's other naps. They are both still in nappies, so you don't get "Need weewee!" just as you settle down to a feed. They both enjoy cuddles and are relatively uncomplicated. I used to have dc1 on my lap while reading to him, so, when I was pg with dc2, I got him used to sitting next to me, holding the book on a cushion on his lap. Then when I was breastfeeding dc2 I could still read to dc1 without anything having changed for him.
We got a buggy board for dc1, and kept a sling for dc2 in the buggy so that dc1 could ride in the buggy if he was too tired to walk. Tended only to happen if we were out for dinner.
Not denying the first 6m will be knackering. But the first 6m is knackering no matter the age gaps. Having 4y and 6y age gaps were worse than the 2y age gap, as the older dd needed to be places in time, like school. Not a problem with a 2y age gap.
As for the ibuprofen, again, please don't let it distress you. Unless you OD'd, it is highly unlikely that you have harmed your baby. It is so, so common for women to take OTC meds or drink alcohol before they know that they are pregnant, and the babies are absolutely fine.