It's brutal. It's not you. It's not fun. I'm pretty laid back but it tested me to the absolute limit and I can't say that I enjoyed that period looking back.
Anyone who is partnered who says they are solo parenting because their husband is working away for a few days, or tells a single parent they're lucky because they "get a break" needs to walk a week in a single parent's shoes. they will come out of it feeling as frazzled as you currently do.
It's not only the daily physical grind, it's the emotional toll and constant decision making and not having anyone to share the burden of worry with at 4am when they've got a fever and you're faced with a pile of sicky bedsheets, you've run out of clean towels and you just need someone to help. It's the bit where they get an excellent school report and you've nobody to share it with, and a million other tiny moments that are really not easy. It is no picnic, but it will change. It's changing in tiny increments every day, but it's hard to notice.
What you do have is autonomy. You are the boss. You get to say whether it's egg on toast for tea for the second night in a row because there's nobody expecting you to cook. There is nobody else leaving a mess around the house, nobody you have to check in with, pick up after, ask permission from.
Like everything in life it's pros and cons and if you can lean into the pros it will be an easier time. Yes, this is hard to do when you're utterly exhausted.This is a helpful website. Laura Markham has loads of online resource too if you can listen to a podcast, they're out there.
In times of crisis, get outside, fresh air, or water so an afternoon bubble bath when you're out of ideas or a jump in a puddle, can reset things. You need to team up with other parents, ideally ones in a similar boat to you, who understand. Not people who tell you you're lucky. Humans were not designed to raise kids in isolation, it's no wonder it feels shit, it's just not what we're meant to be doing but if you can find a Meetup group or something on Facebook locally to link you up with other single parents who you can muck in with, that will make things so much easier. You're doing alright you know, you are.