I'm so sorry, this must be really hard. I think you are totally reasonable to feel betrayed.
DH and I wanted a different number of children at the start of our relationship, he was always open about his preference but when I would say I wanted more he'd say, let's take it one at a time, either of us might change our mind. Which was true of course and I told myself that if it came to it I'd be happy with the lower number.
When we reached his number and I eventually began to talk about another he said he still felt like he didn't want more, he was sorry, he had genuinely thought he might change his mind but now didn't know if we could cope with another.
Even that felt like a betrayal - I had always hoped ofc that he would change his mind, and I remember the crushing feeling when I realised he hadn't. And for you to know your DH has been lying must feel even worse.
It is really hard when you have always imagined yourself with a particular size of family, I felt like I was having to adjust my identity as well as my hopes. The discussions with DH were really hard because, like you, I didn't want to persuade him as such, but also needed to share my pain with him as trying to process it alone was making it worse, like a separation between us.
I'm not sure what advice I can offer, I just wanted to say it's reasonable to feel whatever you feel.
Oh one thing I did find helpful was communicating with DH about this topic via email at first. I knew I'd cry if we discussed on person, and that made me feel like I was manipulating him. We did talk in person as well, but starting on email helped.