please help me debug

I'm looking for advice on keeping bugs out of my apartment.
In the last week, the weird neurological symptoms that go
with my chronic migraines and absence seizures have become
nastier and more frequent, and started to include actual
visual hallucinations for the first time in more than 5
months.(*) This does not combine well with real, live, 6-legged
little things crawling along the edge of my field of view.

I live on the top floor of a brick apartment building.
There's no attic. I think there might be a crawl space,
but I don't have access to it. I don't keep the windows
open (even after I asked the landlord to replace the
screens, they had too many holes in them, to suit me.)
There is an air conditioner, which I have set on "fan."
I mostly see bugs in this corner where I have my desk,
which is between two windows, though it often looks like
the bugs are crawling up from the floor or the baseboard
heater. I also see some real bugs near the door (to the
hallway, shared with other apartments), near where I keep
my outdoor shoes. I've seen more bugs recently, since the
weather started to cool off.

Suggestions for keeping them out or killing them off? I'd
like to avoid filling my apartment with fumes that will
risk triggering migraines, and I'm sensitive to a number
of perfumes and chemical solvents. If you can suggest
something that doesn't have a strong smell, that would be
especially welcome.

(*) I had been calling the distortions in perception
"simple partial seizures," because some of them are so
very like that. But now I am so badly freaked out that
I'm back to thinking of the whole mess as just "weird
neurological symptoms." I'm worried because the anti-
seizure medication that helped so much for more than a
year and a half is suddenly helping less. And I'm afraid
the new doctor I'm supposed to see next week, the first
time I've ever seen an epilepsy specialist, will say
there's nothing really wrong with me, that I'm just
imagining all this nonsense (like so many doctors did
before.) Of course, one side effect of the anti-seizure
medication is anxiety...I know this fear is stronger than
would be entirely rational. Still, I'm glad I don't have
to go to the appointment by myself.

I am also frightened by the thought that I might have
made these weird neurological symptoms so much worse,
for so long, by over-exertion. I suspect the details
of the over-exertion may be relevent, but I will not
share them until some kind person tells me how to put
them behind a cut tag. Those of you who know me well
can probably guess. *blush* Let's just say it's not
the kind of over-exertion I would want to give up.