I would definitely explore your options. High school is a good time to start advocating for yourself because if you had an IEP or 504 plan in middle/elementary school, they will be much more accommodating and flexible. Whereas in college, no one is obliged to offer you extra help. Your professors won't even know you have a mental disorder unless you tell them. So it's good practice for college. Also, you are more likely to get accommodations in college if you have a record of using them in high school.

That being said, I'm a junior in high school and I have accommodations. Talking to the learning specialist at my school was really one of the best things I've ever done. I don't always use my accommodations, but it really helps to know that I can use it if I need it. I advise seeing what your options are and then go from there. It doesn't hurt to inquire about some extra help. I see it as a sign of strength to ask about this kind of thing and I think teachers will appreciate you being proactive and be receptive of your requests.