Swimmers?

I'm still having major health issues after 5 months and doctor has told me to go swimming.  I used to be heavily into boxing and martial arts (even as fat as I am) but these days just moving is painful.  I'd like to start off slow, with just gentle swimming.  Anyone got any tips?
First off, like finding a comfortable place to wear bathing suit! 
Next, how can I ease into this? I have a REALLY tough time motivating myself to do anything on my own, which is why I took boxing and martial arts classes, because the trainers wouldn't let me get away with anything.  Are there such things as personal trainers for swimming?   Any good websites?

Do you think there's a place around you somewhere that offers water aerobics? Very low impact and it's mostly underwater so wearing a bathingsuit becomes less of an issue.

BTW, it goes without saying that if anyone makes you feel uncomfy about wearing one, they can directly go and &%$@ themselves.

Oh thanks Mort, water aerobics might be a good idea