I think you're on the right track, C.! I would definitely give the breast first, each and every time. If you can stomach it, the best way to get your supply up is to *not* follow up with the formula. Yes, he's going to protest loudly at first, but your body is going to produce what is needed, (supply will equal demand,) and the only way it can get there is if more is demanded of it. Breastfeeding "empties" the breast better than pumping. It will take a couple of days, but he's not going to let himself starve. Perhaps plan a couple of days where you have the time for persistance, and just keep him hooked to you all day. ;)
I was in a similar situation with my first son. With my second, he's getting breastmilk exclusively. I was even pumping a little extra every day.
That being said, it was a huge time commitment to get where we are. I couldn't breastfeed OR pump for a few days after my son was born, (long story,) and my suppply dwindled to nothing. It wasn't easy to get him back to the breast and I was in tears at times, (maybe it was the post partum?) and I can't tell you how close I was to giving up, but it was worth it.
Whatever you do, I applaud you. My sister and friends were almost jealous when it looked like I'd just have to use formula because it's *so* much easier than even pumping. You are doing a great job already! It sounds silly, but breastfeeding is definitely the hardest thing I've done in my life.
Good luck and sending good thoughts your way! :)