So, the last 3 weeks when masturbating i've noticed that when i'm close to orgasm and you can feel it's about to happen, when i breathe in the feeling of being close to orgasm completely disappears.
It also kills my Orgasm if i breathe in during one.
Now i can't hold my breath long at the best of times, but on the verge of orgasm it's virtually impossible. i end up gasping for a breath then trying to hold it as long as possible and hope i can reach orgasm before i have to breathe in again, but that inevitably means killing the intensity of my orgasm which i only get one decent one, and they're only about 5 seconds long at the best of times.
I never noticed this before 3 weeks ago, no idea what is going on.
i cant breath during orgasms, i think it breaks concentration or something. you may have not noticed it because youve never tried to before
I tend to have to hold my breath when close to an orgasm. Neer felt any kind of pain though, so unfortunately I don't have any advice 
I think I just forget to breathe !
I've noticed that when I hold my breath I have a much stronger orgasm than when I'm breathing. My partner has also picked up on it so when he wants me to orgasm he'll help me hold my breath.
I know that for me it can make a massive difference keeping breath in as apposed to having empty lungs and I've always tried to breath as little as possible when reaching climax, however often during orgasm can't help excessive (often loud) breathing/gasps - I've never really paid attention as to whether this kills the orgasm quicker though.