Not just you. There is something wrong for sure. My entire guild (only 6 of us right now haha)
is having this same problem. Usually we do OK with FPS but have many spikes down to about 5-15 FPS. Then we try to do warzones and we have such low FPS that it is sometimes hard to do any good for our team.
By the way we dont have terrible computer. We can run games like WOW, Rift, Skyrim and others on max without problems.
This needs to be fix specifically for PVP.