Why Didn't Restylane Work In My Lips? Should I Go For Another Syringe?

It is difficult to assess your situation without photos.  It is not unusual to underestimate the amount of product  needed to obtained your desired outcome (and always better to under correct than over-inflate.) It sounds as if you experienced some swelling after your procedure, giving you a fuller appearance.  With regards to your pain, there are measures you can take to aid with discomfort as well, such as topical numbing cream and icing the area to be injected.   I recommend waiting a full two weeks (the product will continue to add volume in this time) and then notifying your injector if you still desire fuller lips . Most injectors want to please their patients, and will appreciate the feedback.

If you like the way it looked two days later after injection ( often maximally swollen), chances are you need more filler. It didn't go away, it probably was not enough.