OP, you are 3 days post-section & childbirth.
You medically cannot do all the things you are suggesting, and I'm really sorry that others around you haven't stepped up to make sure you are not trying to.
You need to spend most of the day in bed - baby with DH/P as much as possible.
Don't worry about magic for the older DC - just be around for the present-opening etc.
Who is visiting you? If it's your family, tell them you need help. Give them practical jobs to do that will help you, including passing over baby fully, while you go to bed.
Regarding going out for your meal, I guess that can't be changed. If they are your family, be clear with them how you are feeling & do as much as you are able but go and rest / feed baby as needed, and don't stay long.
Have a plan for the next few days that involves others helping / taking other DC out to give you a rest.
I'm upset on your behalf that no-one in your family (DH / own family) has thought of this & is doing it already.
The idea that 3 days post-section you are already home from hospital is shocking (it's 5 days in Ireland, ie if you had a baby early on Monday morning, the earliest you would leave is Friday afternoon or Saturday morning). That's because it's major surgery & you need to mind the wound / stitches.
I really really hope someone steps up to help you today 😘
(PS congratulations on your new little baby! 👶🏻)