Should I disclose my anxiety in additional information?

Disclosing this would not give your application a boost but rather a red flag.

Forgive my lack of decorum and frankness, but if you are suffering anxiety with a high school curriculum within the safety and comfort of your home, then admissions officers would be deeply concerned about your ability to thrive and succeed at a much higher level and living independently from your familiar support system in terms of friends and family and counsellors that know you.

Applying to college is like applying for a 4-year position or post where they are being fairly transparent about what the workload is or you can find out yourself pretty easy, and they want to make sure you are the best possible fit for them, not the other way around. College is not a place to convalesce but challenge yourself to become your best person. If they feel additional time and effort and resources are going to be exerted on your behalf from day 1, well there are other logical applicants that might transition smoother without any risk or liability.

Hope that makes sense to you and I don't like dancing around the obvious so again sorry for any lack of sensitivity you might read in my answer.

As someone who deals with anxiety and depression, I am not going to disclose it because I just don't want to deal with the stigma. But it's your choice if you want to. I would say focus more on the steps you're taking to overcome/get help for your anxiety rather than delving into the details/symptoms of your anxiety. Yes, it's totally unfair and stupid, but you don't want AOs to think you are "emotionally unstable." (Anxiety obviously doesn't make someone emotionally unstable, but this is what I have read that AOs might think, so that is why I am choosing not to disclose my mental health issues.)

Everything on your college application should contribute to an overall positive portrayal of who you are as a student and community member. While you don’t need to hide integral parts of yourself, you don’t want to divulge challenges that will not in any way support your application positively. Mental health issues are not inherently negative. But you should consider whether your application will be confusing or incomplete if you don't address these issues. For example, if prior to this semester you consistently earned A's and your anxiety is now causing you to earn C's, disclosing your mental illness will help explain this discrepancy.

They definitely would not think you're weak. Talking about your anxiety and how you're trying to overcome, it would be appealing to colleges. No, disclosing your symptoms or that you're getting counseling is not TMI because it's a struggle that you're working on getting help on. That really reflects on you as a person because you're not just allowing your anxiety to swallow you whole and take over your life, even if it is trying to.