How big are your callous on your fingertips?? If there really wide you can take an emeryboard and file them so they come more to the point.
2nd ??
what is the action on your guitar?? If it's to high you may be having to use to much pressure concequently flattening your fingertip too much. ;)
Let me know if this is helpful. I'm new to the site.
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Jazz where everything is new. Tricked out and tipped over