The things that really jump out at me here are that your determination of the razor being sharp initially was based on a hanging hair test and shaving your chin for the first time with a straight razor. The HHT is not a reliable test for shave readiness and it can pre-dispose you to the assertion that a razor is not sharp when it is indeed shave ready. The chin should really not be attempted until you are really comfortable with shaving every other part of your face. Your chin is rounded and it is really hard at first to maneuver the razor keeping a cutting angle throughout the round part of the chin. This is normally why it tugs and scrapes as most people really are at a 45 to 90 degree cutting angle when shaving around the round part of the chin. It would not hurt to re-hone the razor and take on your technique a little at a time starting from the sideburn on your dominant hand side down to the jaw with short little strokes and longer clean up strokes. Then the cheek, the other side, the neck and on the chin, I recommend breaking it up into sections like under the lip, the sides of the chin and the round part last.

You definitely way overdid it with the barber hone as normally 5-6 strokes are plenty to refresh a razor. Next time, try just stropping and working on your technique before any corrective measures without getting some help or advise and there is plenty on the forum and in the wiki.

Good luck,

Lynn