Not a psychologist/psychiatrist, but I would try to find where those feelings are coming from. If it's just from a dislike of the subject then I would simply stop reading it, there are certain topics I don't read because I don't care for them. If it really is an irrational feeling and you enjoy the material but feel guilty about it you might want to introspect on why that is. Growing up in a religious background it took a long time for myself to not feel guilty about NSFW stuff, but having identified that as the cause had freed me in realizing that an external component was putting pressure on an otherwise enjoyable activity. In reality since you know its irrational it would be prudent to seek out the source, and if there is trauma involved I would highly recommend seeking a licensed professional to help sort such things out.