Suddenly every song is repetitive

Since the day before yesterday, every song I try to make is god awful repetitive. It doesn't matter what genre I try — pop, rock, symphonic metal, ballad, or dubstep, for example.

I thought it could be the lyric. The length of the lines, the rhyme pattern — ABAB, AABB, etc. Or if words are repeated in lines/song sections...

And I've tried to mix it up and change everything I mentioned, but I still get those monotonous melodies: ¯–¯–¯–_ ¯–¯–¯–_ ¯–¯–¯–_