I'm surprised,

I thought that arrow is supposed to rise a little as the string begins to push it, so that by the time the fletched part arrives at your bow hand, the fletching barely touches. (I know this is not always the case, since I can see the mark on my glove, but my bow hand glove doesn't have a seem where the arrow rests.)

I shoot traditional style with a D-Sectioned Yew longbow and I have no shelf either and I shoot off of my hand. I made a glove up and glued a piece of horsehide on the index finger. It is hide with the hair on and I arranged it so that the direction of the "fur is smoothed by the passing of the arrow on release. Horsehide is very durable and the hair is relatively short. It was a good solution for me. I've had a stray quill splinter get stuck in my index finger when I did.t use the glove (ouch!).

are you pulling the string with your fingers (using a shooting glove or tab) or with your thumb (using a thumb ring, the traditional Mongolian method)

With fingers the arrow will rest on your index finger and you can use a method like Jeffrey suggested.

With a thumb ring the arrow will be resting on the other side of the bow on top of your thumb. The same method will work except it needs to be glued to the thumb of the glove. If you are shooting this way, you could research what the Mongolians used historically, which will solve your problem and bring you closer to historically accurate (if it's important).

-Mike