Just because there is no evidence doesn't mean its not a problem, and don't be ashamed. Anxiety is part of what I have PTSD.
I explain its like breaking a bone, you cant always see it on the surface but it hurts and will take a long time to heal. I know it might be scary or you may not see why but consider therapy, I feel I have found a lot out about myself that I didn't even think of as part of my problem. Good luck x