Breastfeeding & Going back to work

My daughter is 2 months old, I’m going back to work in a couple weeks. I’m breastfeeding and would like to continue to do so, but I only make enough to feed her the exact amount she needs. I take vitamins, eat lactation cookies, drink supplements, pretty much everything I can do to make more milk, and I still don’t have any left over to pump. It seems like every time I make a little bit more- BOOM growth spurt and she eats it all right up and I’m at square 1 again. I will only be working weekends as my husband has a crazy work schedule, he will be home with my daughter. I want to make it less stressful for him and don’t want her crying because she’s hungry if I’m not able to pump enough to last 8-10 hours. I’m not kidding my daughter eats up to 7 ounces every 1-2 hours it’s insane. Any tips on how I can make enough to store some before I go back to work!? I go back September 7th so I have time to freeze some but wondering how I can do that. Or, I really hate to do this but if we have to, I will have my husband give her formula for those couple days a week to hold her over. Any formulas you’d recommend that won’t give her an upset tummy? I’m worried about her getting constipated if we give her formula. Ughhh breastfeeding is hard lol not giving up yet though!