OP, their isn't a general consensus about child-free weddings, but the most reasonable opinion I've seen is that if the Bride and Groom want child free, they will have to accept that some parents won't be able to attend. Then, it's down to the invitees how they want to manage it with regards to who stays with the children and who goes to the wedding.
That, up to that point, you staying home is perfectly reasonable.
However, it does sound from your OP that you're not satisfied with that.
Aibu to say if my ds is not coming neither am I?
This is where you're being unreasonable. There's no 'if' about it. DS is not coming. It's their wedding, and he is not invited. If you say 'if he's not coming...' it appears that you want them to alter their plans to suit you. Moreover, it looks as though you're offering it as an ultimatum.
they think I can't control my ds
This is pure projection and is why you have people thinking you just want to be offended. They haven't said any such thing. If they'd said children are welcome apart from BettyBoo's, then that would have been a judgement and an offensive thing. They've said they don't want any children there. They've said absolutely nothing about your ability to parent, nor have they implied anything about it. They've said they don't want children at their wedding, which might be for any one of several reasons (maybe they or someone close to them has just lost a child?), but you've chosen to take it as a personal slight.