Comment by yogorenapan

I've had this exact problem before, though not with such high amounts. To make it worse, it was Monero rather than Bitcoin, which made tracing impossible. In the end, I just had to produce emails/documents proving I was paid in crypto a couple years back & the associated increase in value since then. I got the crypto into my bank via a sketchy non-kyc exchange and somehow they didn't care about that at all.