camera angles?

I'm not really sure what to do. I've tried every tip and trick, but I can't look up and down. I have tried my keys, I've tried my mouse pad, I've tried my mouse. I can only look side to side. The camera won't let me look up and down, even when I'm in build mode. I can't look up and down, so I'm not sure what to do. It worked perfectly until this newest update. I don't know what happened, but I can't look up and down, just side to side.