I'm sure you've already gotten a lot of great responses. I was in a very similar situation with my little one and I pumped milk for her for over a year so it can be done. I fully hear you about lactation consultants not knowing much about pumping...I couldn't get any help from them in this regard.
A couple of things I learned was to make sure you have the correct fitting flanges/horns/shields. I had to try a couple of different sizes before I got the right fit. The one set that comes with the pump may not be the right one for your nipple. I also found that the flanges by "pumpin' pal" www.pumpinpal.com were THE BEST!!! Rather than having a sharp corner, they are smooth and tapered, they allow you to sit up rather than lean forward when pumping...VERY comfortable. The more comfortable you are the better off you'll be. I also recommend getting a hands free apparatus. Medela has a good corset like things that I used, but there are a lot of differernt ones out there.
Don't milk watch...I know it is difficult particularly when you want so much to provide for your baby, but do something else; watch TV read a book etc..get your mind off what you are doing and try to relax.
Also make sure you are pumping fully. I had to pump for 30min at every go to fully empty..you need to get the hind milk out to produce more. AND pump regularly; I pumped every three hours for about 8 months to keep my supply up. Maybe you are pumping too often; maybe increase the time you pump and lengthen the time between your pumps a little. I stumbled upon the 30min thing for me and found I would have a second let down.
Drink plenty of water!! Get as much sleep as you can!! Some moms benefit from smelling clothes their child has worn or visualizing their child nursing while they are pumping helps with let down.
I know you might be disappointed that you cannot breast feed, but my daughter did great on the bottle and I think it really helped her bond with her dad much more because he got to do more feeding and cuddling with her because I wasn't breastfeeding. He could feed her while I pumped or slept or whatever. So don't feel bad, you are a good mom and a good person no matter what happens. Don't take on any mommy guilt..they'll be plenty of that later!! Feel free to e-mail me directly if you have any other questions or just want some support around pumping.
Good luck to you.