I had a very similar experience to you. Very long labour, lots of intervention and an emergency caesarean. I was discharged after 12 hours and when I got home, there were people waiting on the doorstep. The following day, my brother's siblings and assorted partners turned up (it was a Saturday) and they stayed for NINE FUCKING HOURS. They required lots of food and drink and entertaining. I was bleeding, exhausted, had severe baby blues, struggled to breastfeed and in the end, I locked myself in the bathroom and cried. I'd leaked blood through the only trousers which fitted comfortably over my CS scar, my boobs were rock solid with my milk coming in, seeing my baby handed round like a bloody trophy physically hurt in a way I couldn't describe and I was so, so traumatised from the labour that I couldn't breathe for the sobbing.
It was partly my fault tbh. My BILs and SILs were between 19 and 23 in age, had no concept of babies other than excitement and usually, we loved having them round for as long and as often as possible. They didn't know that I was struggling and I tried to smile through it and thought I was the one in the wrong. I look at the photos from that day and it's a happy family and then me in the corner, white as a sheet, severely anaemic, red-eyed and struggling. I hate those photos.
I will always, always, always regret not putting my foot down.
When I had DC2, I left it up to DH to explain that I would not be having a repeat scenario. People were welcome to come and see me in the hospital (really strict visiting hours) but once discharged, I'd let people know when they could come. Luckily, DH's siblings had grown up and moved much further away so couldn't just drop in and I was in a much better place emotionally. I had a repeat emcs but was prepared for it and wasn't traumatised. I was happier to have them all round for a few hours here and there but I felt in control that time round.
Do it. Be utterly clear. Don't have your first days and weeks mired in a cloud of sadness because you're being treated quite shoddily.
My family categorically did not know they'd done anything wrong and I should have screamed from the rooftops that I wasn't coping.
Your family, if they are a normal, lovely family, should understand your polite request. If they don't, well, tough doodies.