I had a incredibly stressful college experience where I suffered severe sleep deprivation on the regular due to undiagnosed ADHD. I worry that I have permanent brain damage from the experience.
I'd say unless you're experience seriously crippling problems I'd take some distance from the anxiety. Brains are much more resilient than thought. If you have tangible symptoms, consider asking your GP, better safe than sorry.
The human body and brain are resilient and what was, was. You can now focus (pun not intended) on not repeating such an experience and take good care now.
Go find and read some articles about neurogenisis to feel better? Seriously though, as a young adult I bought mephedrone analogs from RC vendors at one time and then later saw all the wild claims of brain damage and inability to sleep afterwards.. Relax, you are still you, and you're okay. It's not the end of the world.
And know that the brain has a massive potential for change and repair. It takes some pretty serious damage to see permanent issues. Most things will go away over time