Mend my Frister & Rossmann sewing machine cub 4?

HI I recently oiled my Frister & Rossmann sewing machine cub 4. I've never oiled it before! Today I sewed with it for 30 minutes and it suddenly went very slow. I'm worried I put oil on the wrong part. I thought I put oil only on moving metal parts...Now in it 'limp' mode It sort of sounds like it's straining when I press the peddle. and there is a slight jingling sound. There is no lint or thread blocking it. Thanks.