As described, having likely fallen onto the tip of your Apple Pencil, the transducer element (that sits immediately under the replaceable tip) may have suffered damage from the impact.
If the metal transducer element is intact, you can try replacing the tip - ensuring that the replacement is screwed snugly into position; you should see a tiny gap, of about the thickness of a sheet of paper, between the tip and pencil body.
When fitted, the replacement Pencil tip should be in-line with the axis of the Pencil body - as illustrated. Any observed deflection in any direction is indicative of a likely fatally damaged Pencil.
If replacing the pencil tip does not resolve this issue, or the tip is not correctly positioned in relation to the pencil body when fitted, then your Pencil is likely to have suffered irreparable damage.
While the standard AppleCare limited warranty does not cover accidental damage, if you have purchased the optional AppleCare+ cover for iPad at the same time as purchasing your ApplePencil, AppleCare+ coverage extends to providing cover for your Pencil - including accidental damage.
You would be well advised to visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your Pencil.
Genius Bar Reservation and Apple Support Options - Apple
