Hi Rylan,
I'm sorry to hear about your anxiety.
I'm going to first respond by saying "I don't know". I have my thoughts and convictions on the issue - but to be straight up and open - it's an area I have been dealing with for years myself. What is spiritual, what is flesh, and what is a flesh issue, but caused by something spiritually, so please take my post with a grain of salt.
What I do know is that while we live in the flesh - the weapons given to us are not for the flesh, but are mighty through God for pulling down strongholds, and imaginations, and all high things that exalt themselves against the knowledge of God, as well as bringing into captivity every thought into the obedience of Christ. (2 Cor 10:3-6).
Our daughter used to have night terrors at night, almost on a nightly basis. We didn't let her watch scary shows, and was quite protective but still she had these night terrors. One night we had a revelation that this wasn't her imagination but it was spiritual. Once we started treating it as a spiritual issue - they stopped, and has never returned since.
I have learned to deal with anxiety in a similar way. (Spiritually, not as a physical condition). I'm not going to say that I've nailed it, or speak from a place of full victory, or that I have a good grip on the spiritual side, just that what I share does come from personal experience.
I suspect we are too quick to rush to drugs and medicine these days as opposed to God. I suspect that we can have numerous illnesses / chemical imbalances, but that in many cases these are causes - not the root cause, and that the root cause is deeper, and the drugs just mask the symptoms.
(I actually believe that most of pharmacudical treatments don't cure at all - they only deal with symptoms and it's in the pharmacutical industries best approach not to heal, but rather to make people fully dependent on them, but that's another story - I just share that with you so you can see clearly that I'm a little bias in that direction, and weigh my thoughts with that).
In the end, I really don't know about these things but what I do know - which
@Hidden In Him has mentioned - God has not given us a spirit of fear, but of love, power and a sound mind.
Philippians 4:8 says "Finally, my brothers, whatever things are true, whatever things are honest, whatever things are right, whatever things are pure, whatever things are lovely, whatever things are of good report; if there is any virtue and if there is any praise, think on these things."
With this, I would encourage you if you're not doing this already - try fasting from the media, and other outlets such as news, etc - especially ones that keep focusing on the wickedness and hopelessness around us - and spend the time you normally would in the bible instead, and/or on a mixture of the bible, and various ministries. Likewise good Christian worship music, if you're not doing either of these things and see if that makes a difference.
My personal gut feeling from what you've mentioned is that it spiritual, and that a lot more when it comes to mental illness is spiritual than we now recognise. But I'm just another voice, biased from my own previous experience which may or may not be relevant to yours. Hopefully my post has something in it that rings true and you find encouraging.