Thank you for sharing and being honest. You are not alone with struggling with it. I have a toddler and I'm due to have my second in a couple of weeks and although I am excited I am also dreading all the challenges and sleep deprivation coming my way. During the newborn months I just felt like a milk machine and the sleep deprivation felt like a form of torture. Midwives and forums would say I would learn what the different cries mean, but my baby only had one cry and it was full volume scream. I also had no support around us as we'd just moved to a new city and knew no one, so we paid a cleaner to do a weekly clean for as long as we could afford that to happen and the day she came was always a good day for my mental health.
I never used our baby bjorn/ carrier thing around the house, but I will be trying that with our second.
Child health nurses and other parents have said it's ok to just let the baby cry in a safe space for 5minutes if that's all you need to feel like you can give yourself some "me time". Listen to 1 or 2 songs you love which will shift your mood, while drinking a coffee/ tea while it's still hot. Don't feel guilty if you need to put yourself first for 5minutes here and there because anything you do which is going to improve your mood and mental state for the next few hours, your baby is also going to be benefiting from. I hope that makes sense.
Use what ever support is out there - your local child health nurses, mothers groups, mums and bubs classes like yoga or pilates, baby massage classes, your GP could refer you to parenting support services?
Parenting forums/ blogs are great but there are a lot of opinionated people out there - one great piece of advice an experienced mum gave me was not to take on any advice at all. You will get friends, family, health care workers and even strangers all offering advice on what you should be doing and for every piece of advice out there, there is the opposite also being said. Once my child health nurse told me one thing and the next day my GP told me the opposite! So only take on what you feel is right for you and your baby.
The new mum time can be a very isolating experience, but just know you are not alone!
It does get easier, a mum friend used to promise me that when I was sharing my struggles with her and it is true. It may not feel helpful in the moment but just know it will get easier and you will look back and the this would have flown (somehow).
Hope this helps.