The suggestions in this thread are good, in my opinion.
It sounds to me like you have nutritonal deficiencies affecting your hormones, neurochemistry, and such. These may be caused or contributed to by diet and parasites. If it were me, I'd go 'paleo' (diet) and do a thorough parasite cleanse (either herbal or pharmaceutical - both work). You should also consider cleansing, generally.
Curezone is full of information on these topics.
Don't give up!
I understand the feeling of wanting to give up. Many people who are chronically ill struggle with that..sometimes daily.
I also understand feeling like you're walking around in a fog and disconnected; when I was at my worst that's how I felt. They're kind of 'I'm here but I'm not really here and I know I'm not functioning at anywhere near my capacity' and 'going through the motions' type feelings? For me, these are directly related to inflammation and/or neurochemical dysregulation. Inflammation can be caused by diet or toxins (the body's reaction to toxins, specifically), generally. The neurochemical dysregulation can be caused by liver dysfunction, which is generally caused by diet and/or exposure to toxins.
That you grew up on a farm strongly suggests parasitosis, to me. Also, you mentioned that everything started around age 4. Was there some trauma or anything significant you can remember around then?
Either way (and I know it's hard), I strongly encourage you to consider diet modifications and parasite cleansing. Both were key to my recovery, and are implicated in most chronic illness.
Glad to help if I can.
Yes, in my opinion, parasites could most definitely cause what you're experiencing. Tapeworm eggs/larvae can form subcutaneous cysts, too. That's called 'cysticercosis'.
Check out posts by ICU and scabdraggr for pharmaceutical solutions, and Barefoot/MH for a great herbal dewormer.
I couldn't believe that parasites were a significant cause of my problems, either, so I get it.
In fact, I resisted parasite cleansing for a long time because it simply didn't 'make sense' .. I'd had a stool test that was negative and just couldn't imagine how some 'worms' (that didn't show up on a test; how little I knew!) could change my neurochemistry so significantly - but they (more specifically, their consumption of micronutrients and production of toxins) do. I resisted until a doctor in Tijuana diagnosed me and outlined a treatment plan.
Parasites can infect anyone at any age, and, unless eliminated, can persist in the body forever once they've established themselves. I've had nearly all of the symptoms you've listed, and nearly all of them clear up immediately following an anti-parasite regimen.
Also, this may not be obvious, but parasites particularly affect those who are significantly above average in intelligence; they're more sensitive to changes in neurochemistry, their brains consume more energy, and their bodies require more nutrients (macro and micro) to produce that energy and regulate their neurochemistry. Any significant disruption in nutrient assimilation/processing, metabolism, energy production, etc. (which a parasite infection can cause) essentially throws a wrench into everything.
And, finally, it feels like you're saying (paraphrasing) 'I'll try the parasite cleanse so I can say I tried it' as if you're just going to 'give it a shot'. I imagine, having read curezone, that you realize it isn't something you just do once and that many have to 'fight' over a period of time before getting ahead of them, and I encourage you not to quit early. That said, if you try it and it doesn't help, it doesn't help.
Are you planning on trying pharmaceuticals or herbs, if I can ask? I've tried many, many herbal formulations and had some success - they do work - but now prefer pharmaceuticals for efficacy.
I've used animal dewormers (Pyrantel Pamoate paste, Exodus, Safeguard (fenbendazole), Valbazen, Equimax, etc.) with good success and have no issue with them. They're basically the same product/drug in a paste or suspension. I was initially reluctant for the same reasons you are, most likely, but eventually accepted that the drugs were the same and that the risk was low, in any case.
I found that asking this question helped: would they give extremely expensive race horses (or any farm animal, or pet) a product that's likely to harm them? The answer, for me, was 'probably not'; there's nothing to gain by doing that.