Hi.. Small foreskin can increase the abrasions, friction and keratinization of the glans which can reduce the sensation later.. Lube usage can prevent it.. Try mint flavored lubes for better effect. It can be psychogenic to, so do not worry. It is not a major concern as you can still enjoy sex with reduced sensation.. The lube usage will make it better.. Foreskin restoring can give permanent solution.. All the best...