I would like to inquire about lip fillers.

Hello. Lately, whenever I look in the mirror, I keep worrying that my upper lip looks too thin and shorter horizontally compared to my lower lip. It makes my impression look a bit narrow-minded, if that makes sense. Even when I try hard to draw an over-lip look, there is a limit, and it's stressful because it goes back to how it was once it wears off.
So I am seriously considering lip fillers, but I can't easily make a decision because I'm worried about side effects and aftercare. I'm really scared because I've read reviews saying that if it's done incorrectly, the philtrum can look longer, or the filler spreads upward over time and turns the lips into duck lips.
If anyone has had lip fillers, I’m curious if you are satisfied. How long does the shape usually last? Also, is the pain during the procedure bearable? Sharing your honest reviews would be a huge help. Please leave a comment!