ok two things - one, it definitely sounds like hunger, so I wouldn't recommend doing any kind of sh/pat or pu/pd.
two - yes, the pumping is frustrating b/c then he doesn't get as much as fast as he normally does. But that's the point - he's taking more out more often (well, between him and the pump) so it will only last for a day or two until your supply increases. You could try giving him the bottle first or at least an ounce or two of it before and the rest after (to cut the edge off a little). But also - and i'm not sure this would work, it's just something I've heard. You could try pumping an hour after you feed just to get the letdown. I've heard that will also help stimulate more production. And/or you could just pump til you get an ounce or two, not until you are completely empty, kwim?
Oh, and a third thing. IIWY, I wouldn't feed before a nap, I'd try feeding an hour after the first feed. That way, you are basically doing the same thing as pumping at that time, only he's doing the work instead. And then he'll be hungrier when he wakes up from his next nap, so you keep the big feeds right when he wakes up, kwim? Also, you can try pumping directly after a feed b/c that will still stimulate more production (as if you were letting him suckle longer) but won't really take milk b/c there's none there. You will also be making sure that he's emptying you out. And are you still taking fenugreek? And calcium and magnesium? And drinking lots of water?
Ok, lots of ideas, I hope something works for you!!