I didn't see your second post ,sorry.
Hoe mush sleep you get will not preserve your supply.
If you don't feed him as and when he wants to feed, will effect your supply. So, in short, you must feed him as he askes for it. Its is a physiological process or demand supply not supply and demand. i.e. the more he demands it, the more you will produce for him.
The sooner you are able to accept this is normal, and this is just the way br fed babies feed, the happier you will feel about it. I mean this in the nicest, most positive way btw!)
It can be frustrating for people looking in, such as your DH or family etc. You will most likely hear many comments such as 'he's still hungry' or, 'he's not getting enough is he wants to feed so soon after last feed' and so on... this is just not right. You are doing it perfectly correctly if you continue how you have.. i.e. feeding him when ever he asks for it.
It can be harder for the DH to look on really, as they want whats best for both of you. I think if you can reassure him that what you are doing is best, then he might feel happier too.
Trying to sleep more, purely for the purpose of preserving your milk supply is slightly misguided.
It does all settle down in time. It might be a long while, but it really will get better. If i'm honest, I think it's more a case that you adapt to having less sleep, so it just doesn't feel so bad!