Pimples on breasts & cleavage area?

Does anyone here have any knowledge or treatment ideas for pimples
that occur in between or on the breasts? I am 48 years old, am
significantly overweight, -working on that one- and live in an area
that has high humidity levels, plus the water here is very 'hard'
water, high in mineral contents and I think may be part of what is
wrong with my skin. It also does not matter whether or not I sweat,
dry or damp weather, I still get breakouts in these areas and it's
embarrasing, painful and just a pain to deal with.

Anyone out there who knows about a skin care problem like this?

Thanks in advance, JMc.