Downhill grades effecting my GPA

I am currently a sophomore in high school with a cumulative 3.89 unweighted and a 4.2 weighted GPA. My freshman year i had a 4.0 the entire time, but the start of my sophomore year my grades began to decline. My first semester I finished with a 3.77 unweighted GPA, but the start of the second term has been a complete nightmare. In the beginning of the second term I missed 8 total days of school in one month due to being diagnosed with a mental disorder. For obvious reasons my grades have dropped quite dramatically. My current unweighted GPA (after midterms) is a 2.8, I strongly believe this is only because of the amount of school I missed and I plan on getting a 3.8 the coming semester.

Will colleges see this as a good thing or a bad thing? Does doing extremely poor one semester significantly lower my chances of going to a good school?

Colleges won’t see this as a good thing, but you will have the opportunity to explain the reasoning behind your poor grades. I’m sure they would be understanding since you have a legitimate reason. That said, the best thing you can do now is work to improve your GPA as much as possible before the end of the year. I’d also keep in mind that your freshman GPA isn’t all that significant – sure colleges see it, but what matters is that you are able to uphold it. As long as you are able to bring up your sophomore GPA to a good enough level (a 3.7, or a 3.8 as you said you think you can get, would both be great!) and then take hard classes while earning a good GPA your junior year, you shouldn’t be too worried. Good luck!