Breastfeeding moms...partial weaning?

So my LO just turned 6mo. I have been back to work FT since he was 16 weeks. It took us 12 weeks to get breastfeeding down where I was A) no longer in pain...bad latch no matter what I did and vasospasm on top of that, and B) my supply was sufficient to finally EBF...I had been nursing, pumping and supplementing BM and formula if I ran out, around the clock and it was exhausting. In short, I fought like hell to breastfeed my baby. And it has paid off! He has not been sick yet to date, other than a sometimes stuffy nose here and there, and he is full time in daycare since July! And I love our bond!!
Here's my dilemma. I don't at all want to stop nursing. And my LO doesn't want to stop. But I hardly can pump much of anything for when he's at daycare. I was pumping 10-12 oz total after 4 pump sessions a day -- yes that is seriously the best I've ever been able to do -- and now I'm down to 7-8oz tops. That is only two bottles, and he needs 4. So he gets formula. I can't let him go hungry bc of my pride. I literally pump up to 45 min and massage by breasts while pumping, I hand express after to try and get anything else possible out, and it is a double electric Medela pump I use with a hands free bra. I take herbal supplements. That's still all I get. My job is stressful and I can't change that, but I try and look at photos/videos of him to help. I'm starting to get so frustrated trying to get enough milk and pumping is such a pain! If it was resulting in more milk I'd stick with pumping. But now I'm considering partial weaning -- letting him drink formula when we're apart (he now is getting 8oz anyway despite my hardest efforts) and just nursing when we're together. I don't supplement at home or on weekends - although I'm starting to think he's hungry on wkends now that my supply is going down and may have to let him too off after nursing with a bottle here and there.
What do you ladies think? Have you partial weaned at all? Any suggestions? I'd love to nurse as long as my LO wants to. Just pumping is not working out well. Some BM is better than none, I know - maybe I just keep on? I'm already so proud of getting to 6mo with how hard it's been for us...