Congratulations on you foresight, and for acting on it!
I was abroad in the last GE. I received my postal ballot a few weeks before election days. Just follow the notice and return it timely, and you’re golden!
If you are worried, you can contact the Council where you registered, they might be able to provide a timeline.
I disagree with his choice to not name the place. Fot starters, I would like to know where not to go eat. Also, those people shaming him will basically get no consequence out of their hateful behaviour, so they will not learn. Loss of revenue would have been a great way to drive the point home.