This is not too late to start exploring ECs. What interests you? What piques you? And it’s not always about ECs at school.
I am not familiar with what’s required for psychology major but I think being a psychologist requires you to deal with people, to have empathy in order to help people. Have you ever thought about volunteering your time for low income population such as tutoring kids from underprivileged background? I know in my area, we have high school students tutoring elementary school kids, our local library have volunteers teaching English for ESL students.
Are there any non-profit where you can get volunteer work?
Frankly, no one knows what is exceptional or not exceptional about someone but not having EC or something that you do outside of your classroom will make you “just a number”. If you want to have something interesting, find something, explore, and that will be your story. You can make it as exceptional as you want to be.
Good luck.