I think it's just a crap stage to be honest, you're probably 10 months or so down the line from starting maternity leave, struggling to cope without any structure to your day, so you set a routine. You then feel trapped by the routine (as you said back for naps and feeding) and feel all hell breaks loose when baby decides actually, that routine isn't for me!
For me personally it helped massively when I went back to work. My week became structured again and I was no longer in my baby bubble, obsessing over naps, how many cubes of organic homemade purée he had eaten, if he had enough tummy time, stimulation time etc.
I look back on it as a bit of a farce tbh, it's like I wasn't me for a bit! Second time round and I'm enjoying it much more, no routine, just fed every 3 hours or so and naps when she's tired.
I KNOW it's a pain reading this but it does get better. Eventually you will get a bit of you back, a bit more sleep, different things to concentrate on (work etc) and you have a new normal.
As a PP said quite a lot of people romanticise parenthood. It's often shit and gruelling and tbh some stages suit people differently. Take a break when you can, let him nap in the pram or car whilst you go to a drive through costa or something and listen to an audiobook or podcast, whatever's your thing. 