Without knowing your particular pastor’s beliefs, it’s tough to say exactly. However, we can generalize based off the description provided: non-denominational primitive fundamentalist Christian sect.
Non-denominational means it is an independent congregation not under any church authority beyond the local congregation. Not unusual.
Fundamentalists are a type of Protestant. Think very old fashioned and strict evangelicals or Baptists. Bob Jones University is fundamentalist. Often, these are Independent Baptist churches.
Primitive simply refers to their belief that they practice primitive Christianity–i.e. straight Bible, no deviation in belief or worship. No “accretions”.
Fundamentalists are different from your more mainstream evangelicals in that Fundamentalists practice “secondary separation”. A responsible Christian should practice “primary separation”–i.e. distancing themselves from false teachers. By practicing “secondary separation”, Fundamentalists separate from faithful, orthodox Christians who don’t practice “primary separation” to their satisfaction. So, you get denounced by Fundamentalists for not being in complete agreement with them even though you are otherwise a faithful Christian.
Billy Graham, who agreed with the Fundamentalists in just about every way, was a victim of “secondary separation” because he was friendly toward Roman Catholics.
And of course, Fundamentalists don’t agree, so they often separate from other Fundamentalists over things like Bible translations and worship music.