(((((((((((((Sunrise))))))))))))
I think i actually posted a similar post to this not too long ago ... but yes, for me anyways, my anger or frustration is definitely related to anxiety. I think that both of those things are just so highly emotionally tolling, that when one gets activated, the other isn't too far behind.
I think that when you get angry or frustrated, you often don't know what to do with those feelings (or in my case i don't) and they just accumulate and it becomes so overwhelming that it turns into a state of anxiety because you're panicking over why you're feeling so intensely about whatever it is you're angry with. Am i making any sense? I hope so ...
My point though, is to not worry too much, and that you're not the only one who feels like this, and it doesn't make you uncontainable or anything of the sort.
Whenever i feel this coming on, i just try and focus on my breathing, and remind myself of where i'm at - emotionally. If i can try and stay in the present, and not let my anger/frustration accumulate, i can better control my anxiety, and sometimes even help get rid of the anger - key word, sometimes! lol