In laws are family and I am sure it is hard to not have thier love and acceptance right now. You made a choice, did what you had to do and maybe (I don't know the whole story) it was a mistake but I bet you learned something along the way.

The most important thing is the relationship between you and your husband. If he has forgiven you and you have found a way together to work thru the difficulties of the past then it isn't your in laws place to judge you. This is between you and your husband. They have loyalty to your husband, thier son, which is normal. They also need to realize that that thier son has made a choice to have you back in his life and they shouldn't interfere or try to make things worse.

All you can do is apologize and live your life the way you and your husband feel is right. They have the option of forgiving and forgetting or holding a grudge.
Don't be too hard on yourself.
Hugs,
Heidu

The highest reward for a person's toil is not what they get for it, but what they become by it.
John Ruskin