Can fillers change lip shape permanently? (photos)

My lips look less defined since having fillers.I'm only 18 so I'm worried I may lost some of my natural collagen by being injected.I was injected in the borders but feel my lips look less defined. The dip in my Cupid's bow was lower before fillers.& one side of my lip is slightly bigger and more defined.Will my lips ever go back to their normal shape or will I be left with the shape from the fillers. Also there's a little area on my lip border where I feel I've lost some pigment is that normal