Hello and do not worry about frog pain, it won't help the frog . Get some Melafix (an aquarium medication, a small bottle should do) and mix per label instructions. Dose daily after water change (remove any carbon from filter if using it) for 7 days or until frog is healed. That will prevent and help fight any bacteria from becoming a problem. Keep us updated in this post and let us know of any changes in color, swelling, or feeding habits. Good luck !