There are plenty of great colleges you can get into without exceptional ECs - plenty of colleges will love your 4.0 and likely offer you some great scholarships for it. You will have options! So you do not need to worry about that.
I think the question that worries me most after reading your post is whether you are happy. Prioritize happiness. Whatever that looks like for you. College will work out, you will be fine, so don’t stress too much about it. Instead, find what makes you happy. Whatever it is. And do more of that. Not because it makes you more competitive for colleges, but just because it makes you happy. That is the most important thing.
(And if you find that your social anxiety is impairing your life, there is therapy for that can be highly effective. Something else to consider, in case you need a little additional support right now.)