Hugs to you. I know that you are feeling a lot of pain.
I think this is where you do a big 180. Summon your strength and do not pursue. If this is what he wants, give him the space and time to have it. This time is a gift to you. He is out of the house and out of your face while the affair drama plays out. At some point you should make it clear to him in a calm manner that you will not live in an open marriage.
The best plan now is to LIVE WELL. Get your act together, get your mojo on and really work on yourself. Focus on your kids. Don't let your H or the OW THINK that they have beat you down (even if you still feel that way at first). Let him wonder why you aren't falling apart.
It is a gift to be apart right now. Your H needs to develop some emotional maturity so that he can commit to a M in the full sense. You both need time to work on whatever has brought you to this point. He may come back but if he comes back and neither of you has addressed the issues , you will inevitably be back to square one. You deserve better. M is not the In and Out Cafe. A H/W cannot be like a kid in a candy store who sees something that looks delicious and wants to taste it.
As for the jealousy? What are you really jealous of? This is no quality relationship that your H has entered into. How can it be when it is based on cheating? The fact that he is being intimate with OW will hurt. Put your pain aside and ask what does he have to offer her now that is deserving of jealousy? If he doesn't address what leads him to cheat, he will always have issues in a R and he will bring the same drama to OW at some point in time.
You can get through this. I hope that you and your H can work it out, so that you won't have to "get through this again". That is the goal. To have a healthy M on a fundamental level. To develop compassion, respect and a genuine love for each other. To meet each other's needs. Not just to get your man or woman back.
Marriage can be a beautiful thing. I hope we all get to experience that beauty in our lives.
