Could be a number of reasons, you will have to find the source of the anxiety. I recommend sincere prayer and then you will have the cause and solution revealed to you.

Anxiety can often have a physical component, such as a food allergy. Try giving up gluten and dairy for a few weeks and see if that helps at all. These are common food allergens and if you are allergic it causes inflammation which can create anxiety. Also try taking a probiotic supplement, a lot of neurotransmitters are created in the gut so a bacterial imbalance can cause anxiety.

The above has worked for a lot of people, but really the root of the problem imo is going to be an emotional / spiritual thing. It could be that you are disconnecting from part of your personality because you find it unsavoury in some way, and so part of your mind rebels and it manifests as anxiety. This is the "shadow self" which needs to be integrated. This can happen if you're trying to be a good person, have strong morals etc. But then the animal part of you which desires power, is lustful etc. goes into the shadows and starts causing emotional problems. The solution is to integrate these shadow aspects into the overall personality in a way which serves others and the higher good.