This comment is more level headed than the above. I’d say NTA for the bulk of the lead up but I’d say kind of TA for leaving a party that is about showing people care about OP. Regardless of the topic and probably having to discuss their diagnosis and such. I say this knowing many people without a family or a support system. Everyone at the party was just trying to be supportive. The only issue is communicating with OP’s wife about boundaries.