I'm 6' 4" and wear hat size 8 ½(most stores don't even carry hats that big). The original strap that came with the Oculus was way too tight, so I bought that Elite Strap off of Amazon. Even that one was tight on my head(but not as uncomfortable). Anyway, after a few weeks of using it, the strap broke just like yours did and luckily I caught the headset before it fell to the ground.
Amazon replaced the strap... but a few months later, it broke again. I ended up buying some cheap knock-off called an Orzero strap for it(was $35 on Amazon). It feels pretty cheaply made, but it's bigger and a bit more comfortable than the Elite Strap. I continued to use that up until I got my Valve Index headset. The head strap on the Index is soooooooo much better than what the Quest 2 has. Fits big heads just fine and comfortable enough to wear all day.
I still look here & there for a better strap for the Quest 2, but sadly.. nothing yet.