Security Officer of our building did break-in in our flat and hared me. Need advice.?

Try to find out what security company he works for and report him. You have to. Yes, he can get fired from his job and he will be mad. His job is to help prevent crime not cause it. Tell the Administrator of the complex and call the police ASAP. You have to report it, so that'll it will be on record if he comes back. Get a restraining order. He'll have to stay away from you. If he doesn't, he'll go to jail. You need to tell your friends. I'm sure they would understand and want to be of some help. They can be witnesses for you. He sounds like a creep.