Hi OP, haven't read the full thread, just your posts, so sorry if this has been said already.
Your choices are definitely not binary between continuing in your current specialty and stopping working altogether. You mentioned not wanting to do GP, which is fair enough, but there is a wealth of other options out there that don't have the unique and messy demands of surgery and which are totally doable as less than full time training.
For example, dermatology, radiology, opthalmology, histopathology, psych, etc all have much less antisocial working patterns. Some of these will also still give you options to use your surgical skills in another setting. You could also consider doing an out of program (maybe research, management or education fellowship) to give yourself a little breathing room.
Additionally, maybe surgery is right for you and the problem might just be your particular training post - some places are more family friendly than others. Have you spoken to your educational supervisor about the issues you're facing?
It also doesn't sound like you have a great quality of life where you are, is moving an option? Or transferring to another deanery?
Giving up work altogether is definitely also an option - I do know some female doctors who have successfully returned to medicine after a long career break - but it's definitely not your only choice here. You have a lot of avenues open to you.
I'd say have a think, maybe talk to other medic mums and weigh up all your options from there.
Good luck, OP.