ocean swimming with allergies or a cold?

this morning i had an awful swim.  i'm the first to admit, i'm not the strongest of swimmers.  i'm a definite back of the packer; the bike and run are my strengths.  i'm also not the greatest in the ocean.  but i get by.  

this morning was different -- and kind of terrible.  i just couldn't catch my breath.  my chest felt tight.  it was a lot like that panicky feeling (and being upset at my inability to get my together kind of turned it into a little panic.)  i couldn't get a rhythm.  i just got more and more tired.  i felt like i had exponentially more snot than i normally do.  i was using more energy than i felt i usually do.  ugh.  it was awful.  i was talking to some other people in the group swim and also to my SO who says he noticed i've been more congested on our runs lately - maybe allergies or a minor cold.  does this happen to anyone else when they swim with some congestion, allergies or a cold?  i don't think i was having a panic attack, but man, something really really felt off.  (after the swim, when i was running, i had the same feeling in my chest - the inability to really get a good, full breath, and the chest tightness with lots of extra snot.)  

with two weeks til my next tri (which has a mile ocean swim, btw,) this was very discouraging, to say the least, and made me wonder if i'm going to be doggy paddling my entire swim in 2 weeks.  i haven't raced in the ocean before ...  i was wondering if anyone else has had this problem or tried to swim with some season allergies or a mild cold?