When we messaged people about DD's arrival we said visiting hours are strictly 2-3 (or whatever they were) but please call prior to visiting.

Also the best thing was we made up a sign for the front door that said "Do Not Disturb - Mother and Baby resting" and put it up whenever I was not up for visitors - it kept people away.

If people are at your house and you need to rest or feed just say:

"I'm about to feed, it will take about an hour so you may want to go to the kitchen and make yourselves a cuppa - and while you're at it can you get me some water? You might want to get lunch/dinner/washing up started while you are down there too"

But if people are sensible they will ring first and ask when is a good time. At that point you can give them a date 2 weeks away so they know they can come over - just not yet.