For me, after some experimentation and ruling things out one by one, I found it to be bunch of things. First and foremost for me it was caused by work. Those lovely insane deadlines from the board are a big source of anxiety for me. Also, what I am consuming. Consuming from a diet perspective, news, social media etc etc. Oh and dont forget the after work beer or two some days!
My solution that has worked was to do the usual diet tidy up, reduction of alcohol, EXERCISE. Then some thinking on a daily basis. Not the cool kids meditation but more just mindful thankfulness for what my life has given me. With all the craziness in the world, being thankful for the little things made my daily existence more content and happy.
Important to take time out for yourself too. Get yourself a hobby or some other interest that sparks a passion in you again. Or just timeout to do whatever floats ones boat. Your time is important. Even if that means getting up with the lark, do it.
I have also found a technique, by accident, when I am feeling anxious or being confronted with a stressful situation in work or other situations. The technique involves a mental note to almost "rise" above or "tape a step back" from myself and the situation I am in. In real-time too. This enables me to detach from the moment, without going into shutdown and see what is causing the emotional build up. Normally, its the lack of understanding, the known unknowns if you get me. Most worry comes to zilch. Remember that.
Hope this helps you friend.