I was in the same boat… One year I had over 10k transactions with hundreds of errors and warnings to work through. I was getting nowhere and wasn’t confident at all of its accuracy. The solution was simple in the end, as it offen is…
- Delete your API’s and never bother with them again.
- Export all your transaction history from the beginning of time from all exchanges you’ve traded on as CSV files.
- Append the CSV files so you only have one CSV for each exchange saved on your computer. This approach makes it very easy to spot gaps in data and avoids duplicate concerns.
- Add your wallet address next, such as Trust Wallet or Metamask. This will automatically include everything on the chain or eth network (no need to add every addresses for each asset in the wallet).
Try this approach and you should be 90% to 95% on your way to a huge sigh of relief. The above recommendations should help to iron out any additional issues.
Note some exchanges only keep 2 years history such as KuCoin so I recommend getting on top of those quickly.
Koinly has proven to be a better sanity check over other rivals, as the reports are always very close to own estimations.
Good luck