Mother-in-law Hell

I am a 32 year old women. I have been with my husband for 14 years and we have 3 children. I always had a good relationship with my in-laws or so I thought. They lived about 300 miles away. Our problems began about 2 years ago when they decided to move closer to us (15 miles away). Things were great at first and the kids loved having their grandparents close. They are truck drivers and were on the road 3 weeks out of each month. The problem was that when they were home they wanted us to spend every waking moment with them. We did not mind going to visit sometimes but We do alot of family things just us and the kids. I believe my mother-in-law began to blame me because we didn’t spend all our time with them. She was really jealous of the relationship we had. She began to try and drive a wedge between me and my husband. She actually went as far as telling my husband lies to try to cause problems. He saw though them and tried to ignore the statements she was making. The problem was I was still in the dark and had no idea she was saying these things. In the end her and my husband had a huge fight and she sent me a very nasty email blaming me for everything. I felt betrayed that my husband kept everything a secret and I had no clue how she felt until I received the email. For the 1st time ever I thought of leaving my husband. We did get through it and my husband is no longer speaking to his parents. They moved 1,000 miles away a year ago and we have had no contact with them. His mom calls his cell but he does not answer. The problem is I feel terrible about this because of my children. I don’t think I could ever be in the same room with them again but I have told my husband that I have no problems with him and the kids talking and visiting them. He just feels so betrayed he does not even want to talk about it. What should I do?