As good as benefits flex seed offers there is just one drawback that and the reason I don't take it anymore which is excessive estrogen.

I'm skinny as well and have never been able to put on weight. That shouldn't be a real concern unless you are deathly skinny. Try to work on the symptoms... Do you have a problem with gluten? I think everyone does to some degree so just make sure the oats you're eating are gluten-free. A lot of Oats on the market have cross contamination.

I would look into oxalates and perhaps going on a low oxalate diet for 2 weeks to see if you feel any changes. If oxalates are an issue you should feel something within 2 weeks.. like old symptoms might come back worse than before, you might have joint pain, urinary symptoms...headaches...etc. The symptoms are what's called oxalate dumping and will be pretty obvious

It seems your diet has a few foods I would expect to find in a 3rd stage candida diet...namely mangos and carrots. Perhaps too much of those might be causing some issues but it sounds like there's a bigger issue going on.

Just wondering before I throw any more advice at ya, but have you done a strict diet before? restricting all gluten, sugar, and all fruits for a while? do you have white coating on your tongue? Are you getting enough fiber? 30g? Literally count 'em up and let me know roughly how much fiber you're getting

Sounds like you are on a responsible and serious diet for kicking candida.

I don't think the fruit would be helping with weight gain or getting a quick die off. The vegetables and fish choices are very similar to mine...I had all those bad symptoms when I was eating 3 servings of fish per day...to make up for the calorically restrictive diet of broccoli and all the vegetables. Now I have 2 servings per week and fill on the vegetables, and beat hunger with small servings of almonds, avocadoes, and rice.
I know that when I had bad symptoms like that, Lentils would really cause a nasty gassy reaction. Everyone's case is different, but what I found common in the success stories are.

Alkalinity (from the vegans living off fruit and greens)
Sugar elimination( It is widely accepted that Sugar needs to be cut to eliminate candida)

We all have a threshold for Sugar until we start feeding candida and flareups. I am more drawn to adding back potatoes and rice in small servings because they have so much less Sugar than fruits. Most people think otherwise, but I will get serious malabsorption from bananas. Since my goal is weight gain, the avocados, a few nuts and a ton of vegetables can get me there a little bit. I put on 6 pounds since going mostly vegetarian in early march. I was so disgusted and sick of the carb cutting and fish eating that I replaced my fish servings with boiled potatoes to eat alongside the greens. I eat the starches now and hopefully make up for them with green drinks. I am making cilantro and water in the blender and a ton of stevia lemonade. It oxygenates the colon and is very alkaline. In looking at oxilates thanks to some posts on here, I ditched spinach and kale for now to see what will happen. I would be pleasantly surprised if my long path to recovery and functioning properly at work was because of overating spinach..something I will gladly to without. As well as all that nasty fish. It might be pricey to try to live off asparagus with an olive oil sprinkle as much as possible, but it beats the price on all the supplements and time spent dealing with the symptoms. Candida got expensive, I let so many things go that needed to be taken care of...Bills paid late, tire rotation. My comments are pretty unpopular here, because I think the overeating of protein is widespread and can even cause candida from an acidic body environment. I encourage you to research about how too much fish can cause all kinds of digestion problems, leading to malabsorption and a vicious circle of trying to feel full from an endless intake of protein.

In my case, the confusion and horrible symptoms would occur after eating protein too. It has to be from an infected liver. Heres a link on how overating protein can be dangerous too.

And the chills are interesting to me. I had horrible chills, I wore my coat inside at work. ( when on fish and greens). I really HATED this winter. When ditching the fish and alkalizing, I got a bad fever..which I guess is the body's way of killing an infection. Maybe alkalizing gave the immune system the ability to do it? Now I am in the sauna every night trying to get a fever for a half hr...I hit the sauna after my now recently intense again workouts. To me the chills mean the body wants us to get warm so it can beat out the infection.

http://www.liverfoundation.org/abouttheliver/info/hepaticencephalopathy/
This is a disease caused by too much protein. I think because of the malabsorption and carb cutting, candida people are at risk. And also, candida could fill the liver or bile ducts and cause the same problem.

Your diet is still feeding candida. You have to remove some things from it to get well.
Jorge.