Whether or not your spreadsheet is sufficient, there's nothing you can do about it now. Just file your tax return as Bsch4477 suggested. It's not likely that the IRS will question it or ask for more information. If they do, give them your spreadsheet and explain that the items you sold were used personal items and you do not have records of the purchase prices. My guess is that they will understand and accept that. But again, it probably will never come up, because they are not likely to question it in the first place. There are going to be thousands of people with similar situations this year.
