If your family are worth their salt, then they will rise to the occasion. You may well be feeling considerably better in 2 weeks time (Christmas Day), but, you’ll be feeling weakened by the effects of having had ‘flu, so you need to speak to your family now, and tell them that, if the celebration is to go ahead at your house then they are going to have to “muck in”, ie, bring things they have prepared so that the onus is not on you and your DH alone. One could sort out the starters, another could bring the veg all prepared, another could bring the turkey or other meat and another could sort out dessert.
You’ve got six adult children, between them they could take on one of the courses, leaving you to set the table, provide drink and nibbles. Discuss it with them now, and also say that this is how following years are going to have to be if they come to you, as it’s just too much for you and your husband to do alone even though the mind of both of you is willing. I’m afraid age has its effects - we tire, we slow down, so it’s time to do a bit of delegating. They might even relish the opportunity.