I feel for you.
It is understandable you feel like you do. Especially since as so many have said, the lack of sleep.
I was the same with Sertraline earlier in my life, but worked out what I really needed was time off, things that helped me do my job (and it is a job) as a mother.
I have been a single parent for the past eight years. DD is nearly sixteen and turned out well. So I must have done something right!
Way back then my midwife gave me two bits of advice:
First. Make sure you empty and repack your changing bag for baby as soon as you come in after walk etc.
The reason she said this is if you are down, it is a struggle getting out of the door anyway and that way if you really need to head out at a moments notice and take advantage of a sunny day. you can.
Second
In the early days she said 'sleep when they sleep'. I had gotten into the habit of doing things when baby napped and actually I was exhausted for that reason.
For the rest
Yes, sitting in a cafe with pram if you can.
Gym with creche very good.
Even college with creche for a part time course you enjoy or childminder if you can . It will get you out etc.
And
don't overload yourself.
It is a job. And it is the most important job you will ever do. Despite what people may say sometimes.
And finally lean on people on here. You can.
I've had my gripes with mumnet but I wish I had had them back then.
They are brilliant in a crisis, or just the day to day stuff when you think
'What on earth do I do about this?
Hang in there. I'ts a very good feeling the milestones you can think you achieved with a child. We are still in teenage years which are a story in themselves. And harder than hard in a pandemic but we do tell each other we love each other. And I do still believe that conquers all.
You're doing good. Honestly. Hang in there.
If you can, get a cleaner. That is someone to chat to, apart from the help they give you. Contact with the outside world is an achievement right now.