Greetings,
Although I am not an expert there are a couple of services I found to be helpful in filing my crypto taxes.
I have used a trading bot to do a lot of automatic trades that resulted in about 12 thousand transactions. So I know what you are talking about. I was pulling my hair out for two weeks trying to file my taxes. I found out the hard way that no tax software, not even TurboTax will process that many trades to list on the 8949. If you were able to successfully import all of your trades to TuboTax then you must have been within their limits. I had to use the "aggregated amount" or summary if you will, to initially file the taxes electronically. This was just the total figures for the report. I then had to follow up by physically printing out all of the transactions from a PDF that was furnished to me by Taxbit (251 pages) and mail all of that to a special IRS address located in Austin, Texas. The IRS wants to see all of the transactions no matter how small.
I used two exchanges, Binance.US and Kraken. I was able to connect those two exchanges to a service called Taxbit.com using the API. They were able to calculate the trades and figure out the cost basis, proceeds, and gains/losses there were. I don't know if Kucoin is supported by their service, however, It's possible to import a .CSV file of all your transactions to them if you can't use the API method. I would go to Taxbit.com and read what you can on their site, give them a try, and see if you agree with the figures. By the way, I was able to do this at no charge.
Another website I found useful is a company called Bitcoin.Tax. They have a lot of information and podcasts on their site regarding crypto taxes.
Another thing I want to mention. Try to do your best to file your crypto stuff to the IRS even if it is not perfect.
The IRS knows that this is uncharted territory and they are not experts themselves. There have been many changes and opinions on the fly regarding this stuff and they're trying to figure all of this out along with the rest of us. If the IRS knows that you made a good-faith attempt to report your transactions you will be in a far better position if for some reason they come calling.
This crypto stuff is definitely on their radar and I know they're very interested in the folks who are not reporting. You may have heard that they have already subpoenaed some exchanges for information on their customers.
As far as how to claim your capital losses, again I am no expert but there should be a lot of information out there about carrying forward any capital losses. Try emailing the folks at TaxBit or Bitcoin.tax, or if you have a couple of hours, try calling the IRS directly. I did this myself. It took 11/2 hours to talk to 3 people at the IRS and they still could not help me with my crypto questions. They should, however, know how capital losses are handled.
Hope this helps a little.
