Why can't I file for free? I'm getting forced to use Delux.

If you clear and start over and enter the same info, it will do the same thing.  One common thing that requires Schedule 1 is student loan interest.

Free Edition cannot handle any of the new Schedules 1-6, but there is another free TurboTax product that can.  I'll tell you more about it in a bit and how to see if you qualifty.  The other product--TurboTax Free File Program (not the same as Free Edition)--can handle all forms with no upgrades or fees if you qualify.

If you want to look at your actual Schedule 1 to see what item is requiring you to upgrade, here's how:

With your return open, click in the left menu column on TAX TOOLS, then TOOLS.
In the Tools window choose "View Tax Summary."
At the Tax Summary screen click in the left menu column on "Preview My 1040."
You can review the info on the 1040 Worksheet, and below it you will find the new Schedules 1-6.
What is showing up on Schedule 1?

We can tell you more about the other free product when you report back.

Schedule one of the form contains a bunch of empty boxes and then a final box:

22 Combine the amounts in the far right column for lines 10 through 21.Enter here and include on Form 1040, line 6 field to left of amount field. Total Income. Which contains my total income.

Then box 33 for "Student loan interest deduction" also contains a number.

Yes, student loan interest is a common reason as I mentioned above.   I'll leave you an answer below on the other free product, and how to switch if you qualify.

cool, do you know if I'll have to re-enter all this data if I use that other tool? Or will it be able to import what I've already done

You'll have to start over with a complete new account there and prepare a new return.  It's a separate website apart from Online TurboTax.   If you try to sign in with your Online TurboTax account, it will put you right back in your current return at Online TurboTax.

One of the FAQs I left below is on how to switch.

Cool, just making sure before I waste my time with it. Gonna go try to find some other company or government site. These ridiculous upselling sites are toxic, trying to force money out of people by wearing them down and targeting them during moments of stress. I appreciate the quick responses from you. But this really shouldn't be something I have to get support on. The base website should just make this known immediately without me wasting 2 hours entering every field.

Sorry it's frustrating for sure.  
The Turbo Free File Program is in conjunction with the IRS Free File program so it's required to prepare all forms with no upgrades or fees.

 You'll have to read the qualifications and see if you meet one of them.  One of the FAQs has them listed.  You only have to meet one of them.    If you have 2018 AGI of $34,000 or less, then you qualify.  Or if you get EIC (earned income credit) you qualify.  Or if you are military with 2018 AGI of $66,000 or less.

Because of new changes in the tax laws for 2018, there may be some filers who can no longer use regular Free Edition this year.   But there a second free product that you might be able to use, if necessary.  I'll provide more info about it below.

The regular Free Edition is more limited this year due to tax law changes.    If you need any of the new Schedules 1-6, for instance, then you can't use Free Edition.    You can read about the new schedules at the link below.  If you click the "more info" link there, it will show you what each schedule looks like.

https://ttlc.intuit.com/questions/4511015-what-are-the-new-schedules

Here are some common things that cannot be handled by the regular Free Edition:

     Itemized deductions
     Business or 1099-MISC income
     Sales of stocks/mutual funds/bonds
     Rental property income
     Foreign Earned Income
     HSA
     Credits, deductions and income reported on the new schedules 1–6, such as the Student Loan Interest Deduction

TurboTax has another free product called the TurboTax Free File Program.  It is free for both Federal and State--IF you meet just one of the qualifications.   It can handle all the usual forms without the limitations of regular Free Edition.

See this FAQ to see if you meet one of the qualifications:
https://ttlc.intuit.com/questions/1900583-what-is-turbotax-free-file-program

The TurboTax Free File Program is located at the link below.  It requires a new account from what you are currently using for Free Edition since it is a different website, and the IRS requires it to be disconnected from the TurboTax commercial products.
https://turbotax.intuit.com/taxfreedom/