Hi Siilo,
Just had a read through of all your thread and I think you've had a bit of a raw deal on here. I can understand why you are totally fuming, its a real kick in the teeth, you feel betrayed and very upset by the actions of your DH.
I would feel this way too, you want to know that they are always on 'your team', on 'your side' but on this occasion he crossed over to the 'other side' all be it for a short amount of time, and I think this is what hurts you so much.
I think the fact this happened while you are pregnant makes it all the more harder for you to deal with. We want our DH to stick firmly by our side, we want to feel secure and safe, things are amplified and become more important when we are carrying that precious baby.
I think what he did tonight has made you feel vulnerable as well as angry which is why you have reacted so badly to this. Am I right?
The point of your post what to get advice on how to deal with this. I think the first thing to do is actually not to deal with it. He knows he made a mistake, he knows how upset you are about it. That'll do for now.
Allow yourself a couple of days to become less emotional about it. You can't change what's happened, he did what he did, so just deep breath and concentrate on becoming less upset and less emotional.
After a couple of days you will feel less angry and you will be able to see the 'wood for the trees'. You will then be able to deal with this based on your true feelings rather than those of tonight which is your initial reaction. And I expect you will know exactly how to deal with it at this point.
Your DH is a good DH, he made a mistake, but he has realised this and I'm sure when you both wake up this morning he'll already be thinking about how he can make you feel better and ways he can make it up to you.
I think a nice cooked breakfast would be a start don't you think?! 
Look, you love your DH, you love the child you are carrying and they both love you too. This is your focus, this is where your priorities are, all this family stuff needs to 'do one'. You have far more important things to put your energies into.
Like I say take a few days out from your emotions, what's done is done, and I think by then you will feel so much calmer about it all.
Lets face it, 'they' are just not worth all this are they?
Best wishes and good luck. x