Lots of immature reactions all around. Do own up to your part in this.
You and your husband need to be on the same page with this, as in all aspects of life, particularly with children. Visits are going to happen, and I don't think that his folks arriving 3 days after Christmas did anything to prevent you from having Christmas together. Yes, I know about 12 Days of Christmas, but did you honestly expect to spend that much Christmas together just with your immediate family? His folks rightfully wanted to see their grandchild.
The problem was in the 7 day visit, and with them staying with you. Now, let's try it again, as in - you saying to your husband - "Let's invite your folks over for Easter. But let's pay for them to stay in a motel." Then find a nice one for them and do just that. If your husband balks, or says you cannot afford it, then agree to have them in your home on the condition that the visit be only for 3 days. Explain that a week is too much; it can be difficult when there is friction between people, to be able to keep it together for much longer than that. And plan activities, either way, whether they stay in your home or not. You'll go to the zoo. You'll visit a playground. Maybe one day your inlaws will take the children themselves, and you and your husband will have an afternoon alone together. Maybe you can find a family-friendly movie house.
In short, you need to (a) be the first one to bend in terms of getting them back into your life but (b) make it more manageable for all. Yes, you're doing the work here, but you're the one who asked, and you feel you are suffering, so you need to be the one to do something about it.
Inlaw relationships can be difficult. Distance may mean that they feel the need to get all of their conversations (including nagging) in at once. But hang in there. If you and your husband present a united front, your inlaws can have a good relationship with your children and can be in their lives, but without undercutting you.