What is the best combination of things to do to help with anxiety?

I have suffered with anxiety for 10 years now, ever since my appendix burst. The anxiety has been triggered ever since then. I’m now 25. I have a problem with being involved in situations I know I have no control over. Like when a train stops in a tunnel. I’m already claustrapheobic as it is, so that really does have the biggest potential to trigger anxiety. Once I have the anxiety attack it feels like I have the longest week of my life and I spend the week on edge, paranoid being irrational. Chest also gets tight as well as head. I over think Things as well. Please could you provide me with some advice regarding this. It would be so much appreciated. Thankyou, Gary.