Hello and thank you for contacting us.
You are describing a difficult for you situation but also common for couples who have different origins. It is very often the case that Christmas holidays are spent with one of the couple's family and to avoid unnecessary grudges that should really alternate each year. In your case, I believe the situation is more difficult as some of the family do not speak English and some others have not kept in touch with you and you probably feel somewhat rejected and unappreciated. Also, you mentioned about your illness which I assume makes you feel more vulnerable at the moment, not wanting to take on more stress and feeling insecure and pressurized.
The key to this situation I would think would be to talk to your husband and explain all these feelings. Talk to him as you would talk to a friend about your feelings without expecting a solution but just to be heard. Do not expect him or ask him to change the plans because it seems to be very important for him to spend time with his family who have suffered many changes over the years (people relocating and living apart). Asking him to change the plans may be perceived as a lack of understanding on your behalf. It would be much better for you though if you felt that he understood you and took your feelings into consideration. So he could possibly look after you while you are there, spend time with you and not leave you on your own and possibly not exceed the time you would feel comfortable spending there because of your illness. Avoid thinking about it or making assumptions of how it will be or what you or they will think etc. All the above should ease your anxiety considerably. If you both feel then that you are looking after each other, then the evening would be likely more pleasant for you. You could also ask him for the two of you to arrange to do something fun during the holidays, something of your choice as an achnowledgement of your effort.
I hope this helps
Please feel free to share any feedback on these thoughts
I am not sure if the characterization of having atypical family attachments helps. After all, we are all so different and each of us is being brought up under different circumstances. What seems to happen though and what would be most useful is for you to recognize these differences and tolerate them more if they are not at your cost. It is down to understanding and compromise. The same should go for your husband and acknowledge that you may not feel comfortable to be around his family all the time as you are not accustomed to this kind of attachment or communication.
Hope this helps
Best of luck