So long story short, I realized I filed my health insurance incorrectly. I turned 26 last year so got dropped from my parents health insurance and started my own with my company. The few months I was still on my parents insurance in 2017 I mistakenly filed as saying I did not have any and took a hit because of this. Is there any way to go back for those few months and file that I actually had health insurance?
Sure. Oh, and congratulations on starting your own company.
First, you need to amend your return. See this TurboTax FAQ.
When you open up your return, go to the Health Insurance tab (at the top with Wages & Income, Deductions & Credits, etc.). When you click this, the next screen should be something like "Did you all have health insurance coverage in 2017?"
Instead of answering "no" or "none of us" or whatever you said the first time, answer "I'll pick who had it and which months". Hit Continue.
The next screen will allow you to indicate which months you were covered. Once you have completed this interview (yes, keep going to the end), your Individual Responsibility Payment (i.e., "penalty") on line 61 on the 1040 should be reduced and then you can print and file your amended return.