low supply... ready to give up

My LO is a little over 2 weeks old.  I'm doing everything to try to get my supply up (currently the most I've transferred in a "weigh feed weigh" is a 1/2 oz) including supplements, pumping, power pumping, letting her BF on and off for hours, drinking TONS of water... and the list goes on.  Had the same issue with my son and threw in the towel and went exclusively to formula when he was one month old.  
When I pump, I get about 10 ml which is better than I got with my son, but still dismal.  It's totally not fair to him all the time I'm spending trying to BF my daughter - he's spending a LOT of time playing on his own.  I feel horrible guilt for this as well as not being able to BF.  I went into this pregnancy knowing supply might be an issue and got everything in order accordingly hoping to be successful.
Anyone else dealt with this?  Ugh... I think I cried more liquid than I BF and pumped today!  Did anyone stick with it and actually find their supply went up?  I just can't take this much longer!!