Unfortunately, there doesn't seem to be either of those two features at the moment. If telling the opposite party to cease their actions doesn't work I would say send in a request with CyberStep contact (
https://www.cyberstep.com/help/mailform) forms and try to get administrative help solving this issue.
(agitating the stalker/fan by saying you'll report them is not a good idea, attempting to probe around with the other person to see why they're doing this could be a double-edge sword-it could end very well or very bad-, ignoring would be a good option but isn't entirely fool-proof, be careful not to leave the situation unresolved though as there may be a chance the situation escalates if the fan does not contact you his obsession may increase because of it)
Make sure you take screenshots (f12) as evidence so that CyberStep has a case to work with.
This might also be a good time to take a break from your main and maybe chill around by making an alt and meeting some new people. I hope you receive the help you need because this sounds like it is becoming an obsessive case.