That's awful to hear man, and is a warning to those who use their homes to punt, even if you are single, it's still high risk.
First off, if you're scared for your safety, call the Police and explain the situation. As punting is not illegal in the UK, you're safe from the law in that respect. Screenshot any texts that come through, if withheld, note the call times and what was said. Also, if you have some kind of recording device, next time that guy calls, record it.
Also please provide the forum with info for the WG in question so we can avoid.
Unless it's an agency with a decent reputation, never give indie WGs your home address. In the past when i did prefer outcalls, I'd offer to pick them up from the station instead of giving them my full address. Worst case, a post code should be ok, because it covers 4-5 houses.