Yes, you should have reported your traditional IRA contribution for 2018 as a nondeductible contribution since the deduction on 2018 Schedule 1 line 32 provided you with no tax benefit. If your 2018 tax return does not show this on Form 8606 line 1 as a nondeductible contribution you'll want to amend your 2018 tax return to make your contribution nondeductible, filing 2018 Form 8606 along with Form 1040X (your AGI will change by the elimination of the deduction on Schedule 1 line 32 even though your tax liability will not) to show this nondeductible contribution (which will result in the amount on line 1 falling though to line 14) and your 2019 Form 8606 will include this amount on line 2 to be used to calculate the taxable amount of your Roth conversion.
