Thank you so much for that additional detail. Some of what you write is rather like what I have been going through. The feeling of motion or imbalance/ disequilibrium when there is really no actual movement is called vertigo, something I know all too well. It certainly can be disabling, and while people with vertigo can have memory issues, simply because it is disorienting to be so unstable, yours seem to be far more than what I would call normal and makes me think vertigo and something else is happening here...but please understand that online no one can state anything as a certainty, all I can do is offer my best guess based on what you wrote.
A bit of background: The body regulates balance three ways: the inner ear, the eyes (what we see) and the central brain which puts it all together you could say. If one of those systems are "off" and the other two cant compensate, vertigo will result.
The problem is, people have many ideas and theories, but no one knows for sure why people get vertigo, and online no one can determine your exact cause. Here are some possible causes, both from the central brain and inner ear.
Possible reasons why people get vertigo include migraines, and I am heavily leaning into this idea for a cause in your case, but usually the vertigo is followed by a headache, though there can be migraine vertigo without headache. Often in migraine vertigo there is extreme visual sensitivity; flashing lights, patterns, and high contrast can make the person feel miserable. That is why I asked about grocery stores; while I do not have migraine vertigo my vertigo is visually mediated and grocery stores are a horror because as you said, there is too much stimulation. I like your analogy "looking from the wrong end of a telescope".
There is also cervical vertigo, which is not well understood at all, thought to arise from injuries or trauma to the cervical vertebrae. This does not seem to describe you.
Head trauma can cause vertigo as well. This does not seem to describe you as you deny it.
A condition called Meniere's disease can also cause vertigo, though that is usually accompanied by ringing in the ears and temporary hearing loss. You don't appear to have this, as you do not state you have ringing in your ears or hearing loss, but no one can state anything for certain online.
Tumors of the inner ear called acoustic neuromas can cause vertigo, but they to are often accompanied by ringing and at times hearing loss. This doesn't seem to be the case from what you write...but again, cant guarantee anything on an online forum.
The most common form of vertigo is benign paroxysmal positional...meaning that on sudden movements of the head, spinning sensations develop. That can be a result of little sediments that deposit in the inner ear canal.
Vertigo also can be a sign of multiple sclerosis.Onset here is typically sudden, and the person with MS will find themselves unable to move their eyes towards their nose, ie look inwards.
A rare brain defect called a chiari malformation can result in vertigo.
Vitamin B12 deficiency can result in vertigo.
Bacteria and viral infections as well can cause vertigo. That was originally the case in my situation.
Last on my list is anxiety; anxiety can cause a whole host of symptoms in people because of its affect on the body. It should be the last thing that is considered as the cause of anyones vertigo. Physical causes should be ruled out.
Treatment depends on the cause, and the cause is determined by knowing the history and the results of a physical exam. In Menieres disease, often a diuretic is given, as well as a low salt diet as salt is thought to be one of the culprits. In BPPV, exercises can be prescribed to settle the sediments in the inner ear. In vertigo caused by bacteria and viral infections, steroids and valium (when the vertigo was truly bad) can be used, in addition to Meclazine (sold OTC as Bonine). In vertigo caused by migraines, migraine medications can be tried.
The length of time it lasts is very dependent on the cause. Some vertigos are remarkably easy to treat while others can be more difficult. Vertigo caused by a cold normally lasts a few weeks to a few months for the truly unfortunate. Migraine caused vertigo can be difficult to get under control and can involve finding the right medication.
I know money is tight for you but this is beyond the scope of knowledge of your general practitioner. The specialist you should see is an neurologist; usually I suggest an ENT (ears, nose, and throat) physician first but as your vertigo sounds like it may have a central origin rather than an inner ear one, Id rather, with you, suggest neurology first. An MRI is certainly something to consider, and a discussion with a neurologist would help determine if its something that you would benefit from. I really think you do need to be seen by a specialist, whatever this is and whatever is causing it is getting worse.
There ARE tests that can be done to pinpoint where the vertigo is coming from (central vs. inner ear) . They include things like ENG's and Rotator Chair and Caloric Testing. Those all look for specific abnormal eye movements called nystagmus; the pattern helps determine where the vertigo originates.
Treatments can include the above (and other) medications, and there are also special vestibular rehabilitation specialists who give exercises to help retrain the brain and help it rewire and correct whatever damage the vertigo did, if there is a vertigo present. There are also visual therapists as well should there be a optical cause or exacerbating factor to the vertigo; as is in my case. If there is a structural defect or a tumor that is the cause, that would need to be treated as appropriate.
What I would suggest is that make an appointment with your doctor and discuss all this, and a referral to a neurologist as needed. I do think since all this is worsening that you need to be seen. Generally, its easier to fix something the sooner it is caught.
Here is a useful website regarding all things vertigo: http://www.dizziness-and-balance.com/disorders/index.html
An outside possibility occurs to me. You may be having some sort of seizure event, maybe an odd complex partial seizure. For this as well you would need to see a neurologist. Information about these are here: http://www.epilepsy.com/Epilepsy/seizure_complexpartial
I realize money is tight for you. Here are some web pages with links to low cost clinics: http://www.needymeds.org/free_clinics.taf
I really and truly hope I was able to help.