Danielle hopped on Instagram and shared a video message with her followers, expressing gratitude for the overwhelmingly positive response to her health update.

As we reported ... Danielle announced Monday she was fighting breast cancer, though she caught the disease in stage zero during her annual mammogram.

Danielle says a big reason she's being open with her cancer fight is the hope her story will get women -- and men -- to get cancer screenings, just in case doctors find something ... as they did in her case.

The way Danielle sees it ... no one wants to hear bad news from the doc, but early detection is a much better alternative to finding out you have cancer much later in the game ... and she's stressing the importance of being proactive when it comes to personal health.

Danielle plans to get surgery and is convinced she's going to win her fight against cancer ... and if you think she seems chill about the whole thing, get a load of her dog.