I've offended my in-laws

Thank you everyone. This is all so new and I'm only just realising how varied people's reactions can be. It seems my in-laws are just going to be the type of people who are focused on their own needs throughout this. I know they are upset but they keep looking to me for reassurance and I'm not going to waste my precious energy on that.
I apologised to each of them individually for being thoughtless and selfish but it wasn't good enough for my sister in law and she's turned it all into a huge drama about how I ruined Christmas. My husband has stepped in now and I'm just trying to forget about the whole thing.
I know this little community on here is going to be vital to getting me through this whole ordeal and I thank you all sincerely for taking the time to send me your thoughts and best wishes. xxx