help!

I've been dealing with this for a while. It's between my boobs, and there is even a ring of red like around the underside of my girls. I wear a DDD 38. I sweat a ton at work. I put an antifungal on it because i read that might be the cause, and also what my grandmother suggested. Is there any thing I can also wash my bras in between laundry? Like hand wash. I just want it to go away. My boyfriend loves my boobs and I just want to be confident again. It doesn't smell to nice after a sweaty work day. I've even put powder and used pads under my bra to absorb the sweat! Please do you have any idea or suggestions.