Sometimes a warm cloth can make you let down more, possibly pumping more often until your body realizes it needs to produce more...I just can't think of anything else right now sorry!
Milk production adjusts itself to demand. So letting him nurse longer or more often will stimulate more milk. By using formula you're actually reducing your milk supply. Yes, he'll fuss at first but your breasts will soon catch up. My kids went through the same thing. Sometimes they just seemed to be hungry all the time; other times they weren't all that interested. My poor breasts just had to figure it out. All 3 of my kids did just fine. My daughter had some digestive problems and couldn't handle anything but breast milk for the first 9 months. That was fun :-p
...also do you let him feed off one side until it's gone then put him on the other side until that's gone as well, sorry it's only been 1 1/2 yrs. since I've had to think about these things, but feels like forever! And I know how important it can be for you to give your baby breastmilk, I felt the same way! Good luck!
i feel you sister!!! i have three month old at home and it was very important for me to breastfeed. she did really well off the bat but at about the second month my breasts were just not producing enough. i drove myself crazy trying her on the breast, she would eat tell nothing left, i would pump to see if i could get some more and pump between feeds trying to stimulate. but i just wasn't producing enough to keep up with her demand. i tried fenugreek the herbal supplement, didn't really help. i have ended up having to feed her formula and get enough breastmilk for about one feed a day. i am very disappointed but certainly have tried many things. sometimes you just can't produce enough. don't stress yourself out as i did. millions of babies survive on only formula so whatever amount of breastmilk you can give your baby is better than none. don't feel guilty