Recommendations to minimize shape? Looking for a secure, flat look.

Hello!

The shape of my chest has fluctuated a lot over the last few years. I started at a 32A, then gained and lost weight and have been setting at a 34D for a while. I HATE the growth of my breasts. I was happy and accepting of them being small and rather flat. I'm so uncomfortable with how they look now in most bras, as obviously they are a bit more substantial.

I'm looking for some undergarments to more or less hide them? Flatten them out, minimize the shape of my chest, keep them pretty firmly under wraps. I'm a big fan of corsets and long-line styles, as they tend to do that to some extent, but have struggled with finding something that is comfortable (and not ridiculously hot) as many of the ones I've tried seem to pinch around the lower ribs/waist area. Bonus points for strapless options, as straps drive me crazy.

Thanks! 💚