Greetings 88girl! I am sorry for the many things that are happening. I hope the desired comfort is obtained.
I am not promising a cure but I can say what I would do.
Yes, it is possible for viral infection to travel down or through nerves and it seems in some cases at least some bacterial also. For infection from the tooth I would eat more grapefruit, kiwi, lemons, limes, for the bleeding, raw kale, raw dandelion, more raw turnip greens, raw spinach. Some viruses run down nerves causing numbness so I would use bay leaf tea an antiviral every 6 hours for a month and follow it with golden seal tea for 2 weeks at least ( but not long term). This is made by boiling water and placing two bay leaves in the water for 20 minutes and drinking if cool enough at that time. For the mercury I would hope to chelate it out a bit by using fresh apple and cilantro in different meals.
I would want an electrolyte check from the professionals if this has not already been done (the doctor can be asked and/ or the records can be checked to find out if needed). I would check to see if the doctor looked for hypoglycemia, or at least get a blood sugar machine and check the sugar when hungry and grumpy. I would also ask for a thyroid check and a Raynaudís evaluation in case the heat intolerance and blood vessel difficulty is caused by that. It is said that obsessive compulsive disorders are caused by streptococcus.
For the low blood pressure I would drink more water. If it continued to be low I would want to know the reason for it such as one of the pituitary hormones (maybe affected by the infection from the tooth) or something happening in the kidneys. Headaches can be caused by meningitis (life threatening if causes seizures later), encephalitis, sinusitis, and abscess (could travel to the brain from the tooth).
For the eyes, carrots cooked and juiced and blueberries. I would avoid putting fruits and vegetables together in the same meal and separate fruit juicing from vegetable juicing. I would avoid sugar, (causes anxiety, feeds bacteria, may cause clots and clogs the system in general) high amounts of fat, grease, meat ( I would use more legumes, nuts and beans with grains instead as they form a complete protein).
I might talk to the opthamologist and ask what he thought before trying the following: For the eyes personally I think I might try a cloth dipped in ice water for 3 minutes. This would cause vasoconstriction ( a narrowing of the blood vessels of the eye) it might stop bleeding. However it should be said that it may also cause less nutrition and circulation to the eye at least temporarily and there is potential for vision loss. Of course with bleeding there is potential for bleeding loss also.
Because of the lumbar puncture I would want to use a comfortably warm heat pack for 20 minutes daily followed by cool for at least 10 days some people have complained of spinal stenosis after this procedure. I might put a heat pack on it may help increase the circulation in the area and help heal it better.
For the heat intolerance I would try going in a private room in the living quarters and pulling the blinds and using less clothes I would sponge the skin with lukewarm water and put the fan on. Peace and comfort.