As you landlord is a HA do you have a Housing Office? And if you do, are they any good (most are useless jobs worths!)?
You could try contacting them and say this is becoming like daily harassment. And if there anything they can do?
Most HAs have an anti social policy. Have you ever seen one, or is it listed on their web site. If they do may make more sense to read that first.
And yes tenants can be evicted for anti social behaviour, but I suspect the HA will not think this is a serious as someone who tried to break down neighbours doors, or other physical actions.
And it will no doubt be a long process.
As you say it is a large block, is there a tenants association or something. If so raise it there, and find out if anyone else is having problems.
Whichever approach, as others have said, you need to start keeping a record of incidents.
As a first step, have you thought of just writing a short note saying you find is behaviour towards you offensive / intimidating / embarrassing / or whatever and could they please stop as it has got to the point that you dont want to leave your flat.
Even if it doesn't work, it will show that you have tried to sort it out, and he just isn't willing to accept he doesn't have the right to approach you in this personal way.
Best of luck.