Too much too soon.
NRE (new relationship energy - the high you get when you're falling in love with someone else) is a pretty heady experience and can overrule everything in life if one isn't careful. It sounds like NRE has your husband reeling a bit, and forgetting about priorities that mean a great deal to him; you, your home, your family and his existing life.
It makes sense that you're struggling, and makes sense that feelings of jealousy and paranoia would come up when you're feeling neglected and left behind. No one deserves to feel this way; to me it's an indicator that things are out of balance.... question is, how do you go about re-finding that balance with someone who is so love drunk that they're incapable of seeing that you're hurting in any meaningful way.
This is the poly upset that I see the most, and identify with a great deal; went through this with my husband and his ex-girlfriend, and it was unbearable. Hugs. Hugs. Some more hugs. Here's some more hugs. Cuz fuck, it's rough, and I know it.
You deserve to be comfortable, and if he needs to take a break and refocus on you to feel happy, that is REASONABLE! It's reasonable to ask for the things that you want and need to feel secure and happy - practice out loud when you're in your car, practice typing it out here - you're going to need to get good at asking for what you want, and negotiating if being open isn't going to damage you, or your relationship/family. It's unfair when you're feeling so uncomfortable - to be responsible for that kind of communication, but it is what it is. It's one of the reasons why I don't have much respect for NRE on the whole - I enjoy it, but I see it for what it is, and don't get too caught up in it - it's like being stoned, in a way....
What is it that you want? Define what you want to feel happy and comfortable.
I am a fan of group talks; they allow everyone to express themselves and for there to be little room for misinterpretation, which spells less room for drama, too. I'm all for independent communication, but it can become one vs. two on either side if all three people don't talk. Any reasonable metamour will take your concerns seriously, and help find a balance between getting time with him and allowing him to honour his connection and commitment with you.
You are not alone. There is a community of people who are here to listen, to talk and help you as you find your way. Finding your voice is a big part of being open, and finding the communication that will help you maintain your happiness is DAMN important.