Do I have to go to this funeral? Having major social anxiety!

The Mother of my serious Boyfriend who I'm technically engaged to passed away, I went to the visitation Today, his 2 ex-wives were there, it was very awkward and stressful, don't think I can mentally handle the stress and anxiety of going to the funeral Tomorrow and doing it all over again, I feel very anxious about it. Would it be terribly selfish and wrong for Me to skip the funeral? Or okay? Thoughts?