That's totally normal for the first couple hundred pages. Just keep reading. Infinite Jest was sort of similar in this regard. But eventually you and the book come together and it really begins to flow. There's some really good stories and ideas in there, even after all these years.
It's worth it.
Trust me, GR really starts to flow and becomes really funny. It’s literature crafted at a super high level of skill.
I guess my point is you start to follow certain characters, certain other ones pop up again and again, and some come and go. It isn’t unusual to page back and reread a bit to refresh. But it really becomes a page turner eventually.
Infinite Jest is much more approachable in my estimation than V, which I understand is itself more approachable than Gravity's Rainbow.
Aside the foot note gimmick, Infinite Jest is pretty easy to follow. The difficulty as such is mostly just the length.
I like DFW quite a bit, but I think Pynchon is the better author. So far I just haven't managed to start Gravity's Rainbow, I was scared off by the hype.