How difficult was breastfeeding for you?

For context, I'm 30w pregnant and a FTM who has been planning to exclusively breastfeed, if I can. I recently received some free formula samples from Enfamil. This got my MIL and I talking about breastfeeding, and I said "hopefully I won't need the formula if I can breast feed as much as possible," to which my MIL shared that she could only breast feed for a few months before resorting to formula because it was too difficult, and that she knows a lot of women who just don't have a milk supply after only a couple of months. She assured me that it's ok to not breast feed and that formula is enough, and it's not worth my mental health to "guilt feed" my baby if I'm not up to it.

So, to mothers who never used formula, how difficult was it? And, to mothers who tried and found that it was too much and resorted to bottle feeding, what was difficult about it? This is new for me, being a FTM, so I have no idea what to expect. Is it the pain? Is it the fact that breastfeeding requires too much energy? Is it both?