Woah, wish i saw this earlier!
I am a swimmer as well. However i tend to be slightly.....crazy with it as i am with a swimming club and we do lots of meterage. Something like 30,000 metres in a week..!
However Pink, do not be disheartened. Just keep at it, it gets easier the more you do it.
I have heard of other strange swimming clubs attempting 100,000 metres in one week, every six months...That's 10 sessions a week at 10,000 metres each time, which each session is 2/2.5 hours! No way is that possible!
(Unless you're an Olympic swimmer, of course...)
Edit: Does everyone hate swimming or something?