What started out as a rash under my breast has now spread to red bumps that are itchy on my ribs and belly. It’s been a few weeks. Nothing helps?

The LOCATION. suggests a FUNGAL infection.
Try an anti-fungal OTC Cream (ask Pharmacist for suggestions...) or arrange for a VIRTUAL consultation on Health Tap Prime for a NEW YORK STATE based physician who could after evaluation treat with ORAL medication!
Hope this is helpful
Dr Z.
Yeast Inf. Most likely secondary yeast infection from yeast that lives on our skin and has gotten under and into the dermal layer by moister break down of the skin barrier.