Should I get Botox for my forehead wrinkles or fillers?

Lately, faint horizontal wrinkles have started appearing on my forehead, so I've been scanning the dermatologist. However, now that I've taken a close look at my forehead in the mirror, I'm going crazy because I can't tell if this warrants Botox or fillers.

When I look at the fine wrinkles that form on the upper part of my face when I open my eyes wide or make facial expressions, it seems like getting a Botox injection to tighten the muscles would be the right thing to do. However, even when I am still with a neutral expression, the middle of my forehead is slightly sunken, and because of this sunken contour, the shadows of the wrinkles seem to look deeper.

This makes me wonder if I need to use fillers to flatten the sunken areas rather than just tightening the muscles with Botox to smooth out the wrinkles. However, I'm hesitant to just get fillers because my forehead is wide, and I'm afraid it might look unnatural with only my forehead bulging out. On the other hand, I'm also worried that if I only get Botox, the wrinkles will go away, but my eyelids will feel heavy, forcing me to keep my eyes half-closed.