Want to leave, but scared of losing my son

I posted a few months ago about how my wife has been verbally and emotionally abusing me. It's gotten even worse since then, with her flying into a rage every morning about something I did or didn't do. Yesterday it was because I had forgotten to light the mosquito coils by the back door. The day before it was because I had been playing with our son rather than washing the dishes (of which there were about three dirty plates). Shes yelled point blank that I "disgust" her and that she "hates" me. It's exhausting and distressing, and if it was just me, I'd have left long ago.

But we have a 3yo child who I adore and he adores me. I spend basically every moment outside of work caring and raising him. We even coslept together. But for the past few months my wife has been accusing me of being an unfit and negligent parent. Her reasons, in my opinion, are trivial, like missing a patch of skin while applying sunscreen or packing the wrong coloured hat in his daycare bag, but she considers my errors life-endangering, either because she is neurotic or because she's intentionally trying to position herself as the primary carer if we seperate.

The thought of having to stay in a hostile relationship fills me with dread, but the thought of only seeing my son half the week or less is worse. My worst nightmare is that I move out a my wife cuts off all contact between me and my son. I don't have the money to take her to court, and even if I did, a trial could take months or even years, by which time my son might not even recognise me.

Anyway, I dont expect anyone to have a solution. I just thought I'd share, and maybe give some insight into why some people stay in abusive or unhappy relationships. Thanks.