The metallic taste and speech issue, the incredible head pain, sounds more like Bells Palsy.

I had Bells Palsy in 1999 and I experienced the same symptoms.

I lost my taste buds to the metallic taste. I had the really bad head, neck and shoulder pain. I had speech problems; could not pronounce words that started with "S" and certain other letters. Since Bells Palsey was on the left side of my face, my left eye stopped blinking.

I hadn't thought about it, but since you posted about your symptoms, I am now wondering if Bells Palsy may have brought on the burning smell for me.

I too have smells that are not real. Well they are real to me but it took me along time to realize I was the only one smelling these things. This happens with sounds too and visual problems. I have been afraid to mention any of these things to my doctor in fear of being locked in the psych ward.
I agree with Mark's advise on the Vicks vaporub. I use this often. What weird things we all have to go through with this problem.
As far as the meditation, start simple just by focusing on breathing in and out. One, two, in, out and you will eventually quiet all the racing thoughts. You can get a lot of good books from the library to help teach you this skill. I hear what you are saying I was resistant to this idea also. It has been the thing to help me most though.
Do you think you have chronic pain? I know you have migraines often but are you in constant pain? I have both and have had to go to a pain specialist. I take MS Contin for pain twice a day and it has improved my quality of life much. I am thinking you might have chronic pain as well.
At least we know that we are not the only ones having these problems.
Brain

I get the burning smell sometimes too... during the day its not too bad, I will sometimes wander around and investigate and just make sure nothing is burning if I'm here alone. If someone else is home, I might just ask "do you smell something burning?"... no one ever does.

The only time is causes a problem is at night... for a while I was waking up every night, a couple times a night, thinking the house was on fire from the smell... after installing a few more smoke detectors and making sure all the batteries were brand new, I started using Blistex (in the tube) at night on my lips and under my nose and that seems to help.

Similar to the vicks, but it is good to keep lips moisturized and if you ever have a cold and get red under your nose, it heals it up right away and takes the "ouch" out of it. The Blistex product has a strong smell to it like Vicks, so I guess that's why it works the same way.

Also, during the day if the burning smell is really irritating me, using strong mouth wash will make it go away for a while.

Starr