Is sleep training inevitable?

I know this is a sensitive topic that fires people up but I’d love to get some opinions.

I took 2 sleep classes when I had a newborn, did everything they said, was going pretty well, but then at 3.5 months old all hell broke loose and nights were out of control bad. I was losing my mind I was so sleep-deprived and started co-sleeping out of desperation after 2.5 hellish months of nightly battled. Now she’s 8 months old and is still a terrible sleeper and I’m just at a loss. When we lay her down in her crib for the night she only sleeps for 1-2 hours before waking up. And if we’re successful at laying her back down we get 30 mins at the most before she wakes again. And naps are only maybe 45 mins IF she even lets us lay her down without waking up and crying. If I hold her she’ll sleep for 2+ hours.

So my question is - do you think sleep training (and by that I obviously mean letting her cry - a little, a lot, idk) is inevitable? I’m at such a loss. I never wanted to do that (not that I judge anyone who does! I just wanted to avoid it and it just doesn’t seem like something I’ll be able to stomach), but I’m so tired and her dad is frustrated and acts like I created this problem (I promise you I didn’t initially, though I definitely realize to finally get some sleep after 5.5months we did resort to some bad sleep associations but honestly I had no choice if I wanted to continue to function).

Help.