Where can I enter my medical expenses as one total for the year and not enter each individual expense?

If you've already started your return and want to go back to enter your medical expenses:

• From the top menu navigation go to Deductions > Medical Expenses Profile.
• From this screen check the box for Medical Expenses - 2017 and click Continue.
• Next click Enter New Medical Expense, and from the following screen you'll have the option to either add individual expenses or a total amount.

If you are just starting your return, identify in the interview that you have medical expenses (see attached screenshot) and you'll be presented the medical expenses section as you step through your return.

Actually, I don't have the option to add a total amount, just individual expenses. I can't see a place to add the total.

Have you tried navigating to the path mentioned above: "Deductions > Medical Expenses Profile". I just added a screenshot to the original answer with this screen in TurboTax Self-Employed 2017.