I think you are being a bit unreasonable. You've made the choices you wanted to make. You're presumably an adult and if you allowed your DH to twist your arm, that's your responsibility. It doesn't work to suddenly demand what you feel you're owed because you suddenly feel it's time your DH started giving something back (going down 5 days to 4). He doesn't know you're changing your approach. He's allowed to be confused. And many women would see it as a privilege to stay home. Not saying you should necessarily choose it, just trying to point out that your DH isn't entirely a bad egg for wishing to keep his professional life intact.
Was it your idea not to use childcare, or was it his? If it was yours, then you are being a little unreasonable to expect your DH to factor this in as if it was really, really important to him when it may not be. Given how men seem to compartmentalise, is there a chance he 'forgot' the big picture that you and he are aiming for?
I can think of very few jobs where it's really acceptable to go from 5 days to 4. Your DH may seem himself as the breadwinner with the most earning potential. This may to cave manish for you, but he may feel a little bit hurt, deep down that you don't seem to want him to do what's he's previously been doing, for the good of the family. I will come clean and say that my DH works to support the family and I consider myself lucky to be at home with the little un. That's not to say there aren't times (on a weekly basis) when I think longingly of work outside the home. But to ask my DH to step down from full-time work - no, to expect it as my due is not something I'd feel it was fair to ask. That said, I do think your DH needs to work harder at valuing your life goals.
Re: the lying. Yes of course that's not on. But that's not really about this issue, is it. Dishonesty is a whole other thread. When your DH was giving you all the reasons why he couldn't go from 5 days to 4 (and I don't think UABU to be hurt and angered by this) he was probably weighing the disadvantages of reduced hours - loss of job security/income/professional identity - against the advantages, and struggling to see them. Now, his position seems to have changed because he's weighing up reduced hours with a professional opportunity. As toadish as this is, he may genuinely not have realised that he was 'lying' to you. My PIL tell each other very weird versions of the truth that they seem to believe at the time.