I don't have time to read the whole thread.
I sympathise, I've had some weird stalking attention in the past, and it is zarking awful.
Has anyone suggested keeping a diary of contact yet? Get a cheap notebook, write down whatever contact you have, including conversations, context, location, who else was present, mood, manner, tone, weather, clothes you were both wearing etc. etc. and then get someone else to sign and date it (NB the signer is not verifying the accuracy of the content, merely the date, showing that it was written on the day). It may be a powerful tool if this goes any further.
I'd also be inclined to keep a detailed record of where you were and who you spoke to every day. If you are at home for long periods with no-one else, call a couple of pals and note the times. You may need the alibis.
I hope this doesn't sound paranoid. You may need these details to rebut mischievous allegations, but I sincerely hope you don't.
Best of luck.