Since you have 2,500+ transactions for your brokerage, your best bet may be to enter the transactions on Form 8949 using summary data from your broker statements. The FAQ below provides instructions. You will still be able to e-file, but you'll need to mail the 8949 (attached to Form 8453) to the IRS.
How do I enter more than 500 stock transactions in TurboTax Online?
https://ttlc.intuit.com/replies/4926553
