Am I being stalked online and in real life?

[luna]

For awhile now, I have had issues with this guy, I'm not giving names, so I will identify them as Person A, B, etc. Person A had been harassing me for 2 years now, he seems to be giving my name out to his friends. He was giving out an email address of mine for awhile, until I had stopped replying to Person B, who was interrogating me for him. I blocked them both from emailing me, as well as blocking them on Facebook. As of recently, His friends, circle, whatever, was contacting a friend of mine that I have on Facebook. How does he know that I am friends with this person if I have had him blocked for a long time? Is he using some program, or does he know somebody with a connection to me, and finding out who I converse with? My friend has been asking me if I know such-and-such person, I tell her either I do, or I don't if I really don't. Example, Someone wanted to add me on Facebook a few months ago, I declined because we had no mutual friends. Last night, my friend told me that this person contacted her. How does he know I am friends with her if I never accepted his friend request? Is Person A giving away my Facebook to his friends? Any kind of insight would very highly appreciated.

I have two of my best friends on Facebook that I have no other way of contacting because one lives in Britain, and the other does not text often, I really don't want to delete my Facebook account for this reason. What should I do?

I need some insight as to if this is just childish games, or if this situation is getting serious and I need to involve the authorities.

Thanks.