Three months old is notorious for short naps, and tiredness, is a fault of society expectations rather than babies, who at 3mo can still be feeding 2-4 times a night.
I used to try and feed in the dark without my 2yo, as DS2 was a quick feeder, DS1 could watch a 10min Thomas video and I’d be back. As I chose to only focus on a main middle of the day nap, I didn’t have a traditional EASY, so not much help with that. I had DS2 napping on the go so I could get out of the house every morning and afternoon, so he did catnap, catnap, big nap (2+ hours) catnap, catnap at that age.