Is this an ongoing thing or is this the first time something like this has occurred? It sounds like some type of oppession that may manifest
it'self every certain number of years.
During this time people and things seem to turn against you and there
is often the sense of an evil presence.
Does this describe the activity?

It sounds like a standard demon oppession situation. There's not
really a lot you can do during the cycle. Avoiding others and
anticipating these evil events can help to understanding what is
happening.  Going to churches may also be fruitless as the priests
who are there often look at those who profess this type of activity
as insane.
This is often related to a curse and the cycles are normally of a
specific amount  of time, such as every four years and often to the
month. The very very bad feeling you mention is understated by
the way.  Also it may also manifest it'self in dreams.
Tell us more about this as it progresses. Don't worry though, the
cycle isn't often very long.