While it seems unlikely she's doing it deliberately, it does seem like she is in effdt gaslighting you, putting the onus on you to work out how to initiate intimacy with her without giving you any indication of what she wants, and then chiding you when you get it wrong. It kind of seems like she's set you an impossible task just to keep you occupied, without any real commitment from her to improving your sex life.
It sounds like you are at a point where it will be difficult to move forward without some form of counselling. She isn't being forthcoming with you, enabling you to understand where she's at. She's neither being clear that she doesn't want any sexual contact (so you'd at least know where you stand), or being clear as to how to move towards intimacy again. It's put you in a pretty impossible situation, because it's not reasonable to expect a relationship with a spouse to be platonic long term, certainly not at your ages.
Unless you find a way to work through this, which sounds like it will need intervention from a counsellor, you are going to get more resentful, because you have been put in an impossible position. She seems like she has no idea how this is affecting you, and is not receptive to you helping her understand this. If she has postnatal depression or untreated anxiety which are influencing the way she has retreated from intimacy, then she needs to get help with this and not stick her head in the sand. It's affecting people beyond herself and she needs to face up to this.
I do wish you well, but it does sound like some more fundamental examination of the relationship, and outside help, are needed, and this is not just a question of learning some tricks as to how to initiate sex.