We have done form 8606 every year since 2018 for our nondeductible IRA contributions, using TurboTax every year. I don't understand why line 2 doesn't keep a running total. For example, I contributed 6500 in 2018 and 7000 in 2019, but line 2 on the 2019 form says zero. Shouldn't it reflect the 2018 contribution?
You have to manually tell it the amount of excess contributions that you didn't withdraw by the due date of the return. Because the program assumes that no one would leave the money in an IRA that is charging a 6% penalty annually so it assumes that you would have taken the money out. So you should have been manually adding all of these excess contributions up each year and paying a 6% penalty on the total until you took it out.
You should consult with a financial advisor and see about getting all of those contributions out of the IRA you've put them in and into a Roth or something. The way you are handling this is a bad idea and is going to come back and bite you.