@cupakm
it happens to me when I overdub that some sound played back gets into the track I'm laying over. I use a SDC array about 80 cm in front of me (2,6 feet) with apparently enough gain to pick louder parts here and there from MDR-7506 or ATH-M50
What are you recording with the SDC? Vocals, an acoustic guitar, something else? If it is a guitar, I'd try to mess with the mic position, pointing it downward toward the guitar: most SDCs are pretty strongly directional (cardiod). For instance, I've had surprisingly good results with an SDC pointed at the pick guard of my flattop acoustic, just where it joins the fingerboard, and angled downward. Or you could move the mic up the neck, say to the 9th or 10th fret, and point it along the neck back to where it joins the body.
If your SDC is one of those with swappable capsules, do check that you have the desired capsule mounted: I found once to my chagrin that I had left the "omni" capsule in by mistake!
Vocals are going to be trickier: I would again be trying to get the headphones away from the axis of the SDC, but that's tougher.
Can you lower or change the mix to your headphones? Maybe drop some of the more bleeding bits (snare, big electric guitars)? Again, it depends on what you are performing; for a vocal, I need to be able to hear myself (preferably direct monitoring with a little reverb mixed in), plus enough of the chordal element to say on pitch, but I don't really need to hear the drums in the cans as loudly as I would mix them for the "real" version of the song.