It so happened that I've struggled with the same anxiety issues as Hip during the past 10 years or so. At first I went the usual route, was offered anxiety medication and it worked well for a while. The problem with this type of medication for me was that, after a certain period, say 2-3 months or sometimes longer, its effects would start to subside. As I've later learned this is a common phenomenon of any SSRI medication usage, which basically means you have to either upper the dosage or change into another type of SSRI. This only serves as a viscous cycle as you eventually end up at the max dosage and out of further options. This may take years for some persons, but for me it was rather a matter of months. Besides this, the medication offered resulted in side effects, mainly sexual, but also cognitive, in which I literally felt dumber after staying long enough on a certain medication (luckily this effect turned out reversible). At this point it became clear that SSRIs (at least for me) only treated the symptom instead of the underlying problem.
The last couple of years I have spent a lot of time looking for alternative, natural treatments. What brought me to think about the inflammation/anxiety connection was that I've suffered from a weird neurological symptom as well, which includes pain and tingling of my legs and hands. No doctor has ever been able to diagnose any specific neurological disease, but I was almost certain that this, call it "nerve inflammation" I had, was related to my anxiety. This again brought me to think that both of these issues were symptoms of an underlying viral/bacterial infection. I found a doctor who was willing to run a test on a number of bacterial infections, which revealed I had somewhat high antibodies for Mycoplasma. I was given a long course of antibiotics (even tried a couple of different), but this absolutely changed nothing to either my anxiety or nerve issues. This has therefore lead me to believe that the issue is viral.
Finally few weeks ago I stumbled by accident across flaxseed oil capsules in a local shop. This was one thing I hadn't tried since fish oil is always the advertised one in my country, which I've been taking since long, with little improvement. To my big surprise, I noticed almost straight away after taking flaxseed oil that something was different. My thoughts were more organized, I felt a weird sense of calm which I hadn't experienced in years. About 80% of the "extra" racing thoughts I always had seemed gone which meant I literally felt like reborn.
I've now been using the product for a week, and I still seem to notice more improvement. It's not as if everything is cured, but the difference is remarkable. The dosage I've been using has been very small even, only 2 capsules a day, which is almost certainly less than 15 ml in liquid form. It really does make me wonder what ingredient in specific resulted in this improvement, as it cannot be the EPA/DHA that is present both in fish and flaxseed oil.
After reading this thread I will most definitely try all of the supplements posted here, once I get a handle of them. Ultimately I would like to go one step deeper and understand exactly what virus might cause this and how to improve my immune system's response to it. But I'm afraid it will take a long time before I get anywhere close to the answer...
Btw, at the moment I am only taking flaxseed oil, vitamin D (40 microgram, for general health) and a supplement called carnosine which is very popular in my country (seemed to help a bit with anxiety as well, but nowhere near the flaxseed oil effect).