Extremely stressful weekend in UK

I arrived on Thursday morning in the UK.
Being with the family was nice.
However, things started going wrong yesterday (Saturday) evening when I walked out of my wife's friends BBQ at 12.30am.
My wife's friend is a bigot (wife agrees) who only has her opinion and shouts everyone else down.
Anyway she was sounding off about a family get together and how she didn't want to do it etc. Now bearing in mind some were there at the BBQ, they all kept their mouths shut.
I, however couldn't and suggested that perhaps there was another issue and that is family values. Perhaps other people thought it nice to do something that had family together just once a year.
At this point she started shouting (she is an alcoholic) and approached me on the fact that she knew more about family values and she knew more than me. This was about to launch on me never being at home with the family, but away working earning money.
I then got up and told my wife, that I would be in the car when she was ready.

This was the first and the second:

My wife explained that a nephew's new baby born looked like a Japanese person. My sister in law agreed and that was what they used to say about our nephew and they laughed about it.
I went to a family function today and asked how the jap baby was and I was slated by my sister in law.!!!She was upset! Why when she had been laughing with my wife about it?

I also went today, to explain to my sister why I am not going to her daughters wedding, due to my values. I hope I did this ok, as I wouldn't want to hurt my sister. My parents told me years ago that if the kids are not invited to a function, that they wouldn't go, so I have done the same for many years. Also, I find it very hypocritical to go to an invitation when those people haven't contacted you before, or even sent a card of any sort etc.

At this point I have now come to realize that I am socially inept and really shouldn't have any friends at all!
The few friends I do have usually understand me and don't get too upset at what I say, or do and I treasure their friendship immeasurably!