Massive crypto losses in 2021, some gains in 2024, and now im worried about capital gains tax.

I assume im in a similar boat to a lot of people. I lost a considerable amount of money on 2021 in crypto and have gained a small amount of that back in 2024. If the taxman looks at my gains in 2024 they will assume i owe at least some capital gains tax as my profits were above the threshold. Has anyone found a good tax calculator for crypto that allows for losses? i am currently trying to use Koinly but its incredible inaccurate, it misses out several losses via futures for a start. Any advice on tools to use / has anyone paid any crypto related tax, what were your steps?