@Ruth584 Your listing looks lovely. My first piece of advice would be to raise your prices: $16 is way too low, and as a result, you are likely going to attract some bad guests. I'd be surprised if people could get a hostel for $16 a night these days. Look at your local competition, check what they're charging, and charge accordingly. Airbnb price tips are ridiculous: do your own research.
Second, figure out what type of guest you would like to host, and tailor your listing and vet guests accordingly. As a woman who hosts alone, you can specify that you're only going to host other women. That may make you feel safer: something to think about, at any rate.
In future, if you feel unsafe, I would call Airbnb right away rather than messaging them. The number in your area is 44 203 318 1111: make sure you save it so you have it handy. They can intervene on your behalf and cancel the reservation. If you're really feeling unsafe, don't be afraid to call the police.
I hope that things improve with future guests. Your place looks lovely and you already have some great reviews.