Hi Mommy to a Monkey,
Maybe you can fit in an extra feed during his A time and see if that makes a difference? It could be that he needs more...especially depending on his weight. (He is darling by the way)
I think you mentioned your DS is 8 mos? Also, just want to commend you on EBF as it is sooo good for them! There have been several times that my family and friends have wanted me to formula feed our baby due to her extensive allergies (which means I have to cut wheat, milk, eggs, nuts out of my diet) but knowing the nutritional value of BM kept me going. Ultimately, you know what is best for your DS but just wanted to encourage you to keep BM because this is THE best thing you can give him =). When my supply went down a bit due to going back to work, I would pump an extra time at night (both sides) and it helped my supply to increase a bit, but then again, I am not losing a great deal of weight like you. Maybe talk to your doctor first, as your health is equally important...
Good luck.
Also, I was just wondering, when you mentioned that he only had one nap yesterday, after that nap and some more A time, did you try putting him down and he didn't want to go? What happens if you try to put him down? The reason why I am asking is because two weeks ago my DD would refuse to go down and after realizing that it was because I was trying to put her down when she wasn't even tired made a difference...Maybe looking at his behavior when you try to get him to nap, can help?