Is my motorcycle battery hosed?

Brand new battery from a few months ago. Yes, I left my accessories on for two days so my battery was completely dead. I couldn’t even hook it to my trickle charger. I was able to get a tiny bit of voltage off it from my voltmeter.

I hooked it into my car battery (while it was off) for n hour or so—enough to give it a charge so my 2A/6A trickle charger could charge it up. Once the trickle charger told me it was full, I tried it on my bike. It powered the headlight, but couldn’t turn over the engine.

I plugged it overnight again to the trickle charger, same thing.
I tried plugging it in for a few hours to my car battery, same thing.
I tried plugging it it for a few minutes to my car battery while the car was on, same thing.

So, is it hopeless? Do I have to go and buy another battery?