P.M.
The main issue of you not having much to pump now is that your supply has matured and become tailored to your child. The best time to pump and get stocked up is the first 4 months.
After saying this... try these things, and it should improve.
1) oatmeal!
2) keep very hydrated and eat at least 500 calories more than usual of healthy foods
3) Either add Blessed Thistle, or get the Fenugreek/Blessed Thistle compound. They work with each other to boost properties of both herbs. With fenugreek - you should be taking enough so that your sweat and urine smells like maple syrup. If that isn't happening, you aren't taking enough.
4) pump pump pump - pump a lot more than you usually do.