Offsetting Capital Loss, page-24

I would concur with HelloU. You really have no choice but to create a spreadsheet to get things under control. I have one that lists all the Buys, all the Sells and then the trades which matches the Buys and Sells to calculate the gain/loss whether it be for CGT or trading. I have a flag in the Buys records to indicate whether that Buy has been sold (and is now part of a trade) or is still open. You have until end of October at the earliest to get this done.

Even though you may regard yourself as a trader in relation to some Buys and Sells, I suspect that the ATO may treat you as an investor for everything. This is because to be regarded as a trader one of the criteria the ATO uses is "Organisation in a business-like way and keeping records". Clearly by you own admission you have failed to do this.

As HelloU said, even if not classified as a trader you can carry forward your CGT losses for future years and write off against future CGT profits.