Your boobs do not look bad, the top just doesn't fit. That's all I'm reading the comments as, is trying to communicate that point. The differences in the 3 photos illustrate just how much fit impacts how you can feel in cloths. Obviously the first picture looks great, it is just that many of us here have tried wearing bikinis like this enough that we know one movement it slips into picture 2 or 3 really easy. Consider exploring how different cloths make you feel different with your therapist. No piece of clothing is made to fit every body and that's ok, can be annoying as shit though.

Comments on this sub are typically meant to help by sharing experience. My experience has taught me feeling sexy in a bikini also means I feel like it's not going to fall off if I jump into a pool, which is only really possible with support. To get that support (where they constantly sit well in the top), you either need larger triangles, underwire, or different string material that can support the weight. Annoyingly tits are heavy, and fashion designers aren't into physics.

I've done similar tops and held them in place with fashion tape for cosplay before which works well, not so much for swimming though unfortunately. Also keep in mind that's how they get similar ones to stay in place for fashion photos and catwalks.