The not having kids part I know I Will eventually get over
Well, I think you're a fool.
Once he knows he can lie with impunity, he will do.
Not that I would ever lie to anyone (certainly not on this scale - I might deny having watched the next episode of Killing Eve without them), but if I did, I couldn't respect someone who was willing to just accept being treated so badly. People will do what they know they can get away with.
I mean, how little would someone have to think of themselves to go from discussing and being excited at the prospect of children with someone to accepting that same person lying about having a vasectomy in secret?
You are prioritising a liar over the plans you had for your own life. That's just unfathomable to me.
And the sad thing is that, when you are another decade or so down the line, I think it's a decision you will come to regret.
Even if you made peace with not having children, you would eventually come to resent the fact that he did this and you allowed yourself to accept it.
You tend to see disrespectful behaviour through less sympathetic eyes the older you get.