Hi, Neel, I'm not surprised that you nearly divorced over your DH's reaction to the birth; it is unreasonable - lacking reason in the purest sense of the term - to blame a mother for that sort of birth problem! His blame was entirely mis-directed then, which ought to make you think it is mis-directed now. It is mis-directed and, contrary to his stated intentions, actually bad for your child; he is probably convinced he is "saving" your child with this nagging and criticising, but he ought to understand that your child's interests lie in making the child happy and making its mother happy, too (or not making her unhappy and undermining her).
My DH often goes mad and swears when DS is hurt in my presence, even when, for example, DS has flung his head around and hit a door frame as I am carrying him. If anyone else is sceptical, I can confirm that it is very hurtful and quite offensive to be accused of hurting DS, or even not protecting him from unexpected bumps and falls.
So, what for you to do, Neel? I don't think a divorce is the answer, because that will not solve the problems you have with DH and MIL; in fact, the problems would get more bitter as you fought over DS, money, access, etc. You didn't indicate why MIL is looking after DS, but if it is because you cannot afford a nursery, despite your working full-time, then money and childcare arrangements in any divorce could be particularly difficult, and you could be left with continuing contact with MIL (and I'm not sure whether a divorce would grant separation from her!).
Counselling is probably the only answer, since you want to address the problem itself, and also since it makes DH acknowledge you. He must face that you have concerns, you have a grievance, you are unhappy. He is not the only one here, as it seems he is thinking. He may claim to be concerned about your DS, but it sounds more like the focus is his own feelings of helplessness and desire for control to deal with that. You haven't mentioned how much DH interacts with DS, but does he avoid holding DS? Even if he is Mr Grace and No-Accidents himself, so what? He still shouldn't treat you like this for being clumsy. I'm clumsy, but even my DH doesn't blame me as much as yours seems to.
One other thing you can do, just to make yourself feel better, is to consult an expert, e.g. a solicitor or the Citizens' Advice Bureau, to settle in your own mind that your child would not be taken away from you even if you divorced. You can have that at your back, to lean on when you need support, whenever things are difficult with DH and MIL.
You also said that DS trails after you and loves you, and it would be quite easy to prove his attachment to you and therefore his distress if you were "taken away". Keep that in your heart.
I'll check back later.