Hi P.,
I've been exclusively pumping since my daughter was about ten weeks old. I struggled with her latch during almost all of my maternity leave! I went to BF support groups and various lactation consultants, but nothing ever helped. So, I decide to enjoy the last two weeks at home with her and exclusively pump.
Since my daughter wasn't taking much at the breast, my supply went way down. It took some time and effort to get it back up. I actually ended up taking reglan, along with fenugreek, oatmeal, mother's milk tea, etc. Finally, though, I was producing more than enough to satisfy her.
EPing is a huge commitment (as I'm sure you have already realized). It's so time consuming and you are tied to the pump. It's not like a nursing mom who can BF anywhere and anytime, sure there are portable pumps, but you can't pump in public.
When I was trying to build up my supply, I pumped 9-10 times a day. Once that was established, I could pump 6-7 times a day and still get enough, just not a lot of extra to freeze. Now that my daughter is 6 months, I decided to only pump every 5 hour or so, that's 4-5 sessions a day. Today is actually the first day that I've had to send her to daycare with a little bit of formula in each bottle! I'm about six ounces short.
Anyway, feel free to email me. I'd be glad to share any of the experience I've had if you want to know more. My email is ____@____.com, one more thing. My daughter never had trouble gaining weight. If she was hungry, I always fed her -- either expressed breast milk or formula. I think that's the most important thing, of course. Best wishes!