Grace, I hope this will help, but there will come a time when you just don't care anymore about what he is doing or not doing. Right now you are stuck in the rawness of it. And I think your H has been particularly cruel in his trickle truths to you and implying that this was temporary, when it clearly wasn't, and now claiming you aren't doing the dance right so everything is your fault. This is what they do. They lie, lie, lie. They project and gaslight. Anything to get you off their back. Any story to tell people to justify what they have done. THIS IS NOT YOUR FAULT!!! Don't buy into his BS. [The buying the house excuse after the tax law change is the most ridiculous thing I've heard].
Here is the stone cold reality. You don't want to be with someone who does not want to be with you. You can't reason with someone who is unreasonable. You can't have a rational conversation with someone who is irrational. You can't talk someone out of their feelings. Everything you say to him now is a wasted breath, just a further excuse for why you are awful or unsupportive or fill in the blanks.
Imagine if you could reach the point where you just did not react. Where he got nothing from you. When every time the toddler turned around mom had her back turned. Imagine how scary that would be for him. Now imagine every argument, every fight, every accusation as just further evidence of how you are right where he wants you, how awesome to have two women fighting over him. How empowering that must feel.
Do your best to take your eyes off him. Move forward with your life. Make your like what you want it to be for you. If he catches up with you in the future when he has played out the futility of his fixes, great. If not, you are way down the road on your path to healing and creating a meaningful future for yourself.