I had all kinds of issues with my son for the first five weeks. And then suddenly, it clicked, and I have to say, I'm very grateful I stuck it out to get to that point. 5 weeks of misery pales next to the 52 following weeks of bliss.
I wonder if you're overthinking the whole thing. I think one reason woman, like myself, have such a hard time breastfeeding, is because we have bottlefeeding expectations, where we can measure consistency and ounces. I'm going to gently suggest that the bottlefeeding when your milk isn't coming is, is part of the issue.
Breastmilk changes from day to day, and from feed to feed, and even throughout a feed. That's normal. And if your baby is still hungry after nursing, the best thing is not to pump and bottlefeed; it's to nurse some more.
I nursed my daughter very different than I did my son. With my son, I schedule fed him, I pumped and cup fed him. With my daughter though, I demand fed her. For as little or as long as she needed. I didn't have any of the problems I did with my son. I think my approach created the problems I had with him, and those problems melted away as I gained confidence and comfort with being a mother.
Nobody can tell you how long you should put up with being miserable; only you know your threshold. But if you are feeling guilt, then you know you have not reached that threshold yet. Stick it out one more feeding, one more day, until you do reach that threshold, or it gets better. Try not to put sdo much pressue on yourself, and try not to over analyze each days feedings. If you nurse when she's hungry and avoid the bottles, she'll have enough, and your supply will settle down.
You also should know that it doesn't have to be all or nothing when you do reach that limit. You can bottlefeed and also continue to breastfeed if you want.