I felt a lot like this in the baby stage of motherhood. It is because it is exhausting, unpredictable and all consuming in those early months. Especially when people are constantly expecting you to enjoy every minute of it.
I constantly looked at other mums with babies who seem to love every moment and wondered what was wrong with me or parents with multiple children and thought how can anyone do this more than once, they must be mad!
It's because it is such a huge life adjustment to make and no one can prepare you for it. You don't understand until you're in it.
I felt very similar to how you describe...to begin with and I didn't have PPD (it actually frustrates me that should anyone dare say they dislike motherhood or are struggling to adjust that they automatically get labelled with PPD when actually it is just a huge adjustment that takes time) that being said, if you feel you are struggling then there is no shame to go speak to your GP. But just know lots of new first time mums do feel like this initially, I was one of them.
What I will say echoes what others have said - it does get easier and slowly but surely you start to feel like you again.
You'll never be the care free person you were before, and you will at times look back at your old life with rose tinted glasses and long of the lack of responsibility and ability to do what you want when you want. Of course it goes without saying that motherhood comes with an overwhelming sense of responsibility that at times can be suffocating but it's because suddenly you have this tiny human who you are the world to looking at you for its food/comfort/safety and in return you love them so much you just want to keep them safe/protected/healthy and loved. Motherhood is a lot. But it is worth it.
My DD is 2.5 yrs old now and I love being a mum... I seriously doubted how good a mum I would be after that first year because the baby stage was not for me.
As soon as she weaned, then hit 1 year old and then began walking at 18 months, life changed.
Going back to work massively changed things for me, it gave me my independence back and allowed me to just be me for a few hours a week which was a game changer, instead of dreading the long days at home all day with a baby, I actually got excited to come home from work to see her and then planned things in for my days off together.
Now at 2.5 life is soooo different to the baby stage, she plays well independently, eats independently, she is funny/loving (yes the tantrums are insane) but for the most part it's like having this little buddy with me to go on adventures with. We can eat out at restaurants, go shopping, days out etc.
Not sure what your support network is like but me and my husband are now able to go out for the occasional date night/ cinema trip or can leave DD with auntie or grandparents for a few hours or over night now and again if needed and this means that sense of who we are as individuals and husband and wife has returned instead of us just being mum and dad. So this has helped, but appreciate everyone's circumstances are different.
You will find your feet.
You will sleep through the night again, you will be able to eat out again and go to gigs, you will stop dreading eating out in restaurants and going out in public (which by the way don't not do it just cos you're afraid your baby will cry/kick off, it's all part of it and it's actually quite empowering when you choose to just not care what others think if your baby/toddler is having an almighty meltdown, chances are most people nearby will have kids and have done it all before anyway).
You're still in the trenches so go easy on yourself.
The first year of becoming a new mum is hard work and isn't a reflection of the whole parenting journey, it's you and your baby figuring each other out but you will get there, and they're only babies for 5 mins when you look back, same with toddlers, then pre-schoolers, everything is a phase and it goes so so fast. The days are long but the years are short - I've never heard a truer statement since becoming a mum.
Take care of yourself x