Camera issue or something

[dxltv]

I don't know what happened, but I play a bns mode, and a while ago everything was ok, LMB and RMB keys served to fight, and now i turned on the game, and when i was clicking LMB the camera started to changing your position, I mean it was straight ahead and how I pressed the LMB it was in a completely different setting.. So the question is, how can I fix that? I didn't change anything from last time I was playing, so idk why this changed.

Help me, I'm tired, because i tried even classic mode, but it nothing changes. When I press RMB its the same thing. >.>