You are doing the best thing you could possibly do right now - letting out how you feel. That's what you need. Just shout it out bro. Tell it like it is.
If Eric shows up, there isn't a reason in the world why you have to let him in. Just tell him go away, fuck off, or whatever. As you say, it's YOUR house. YOU live there. Why should you be the one who backs off.
But I agree with the guys who are cautioning you to stop short of starting a fight with him. I really do understand why you want that; you're not 5 and defenseless anymore, yeah?
But being 17 now, do what is REALLY best for you. Stay out of trouble. Don't give the fuck any satisfaction. You know waht these guys hate most? Being ignored. If they can get attention - any attention - they love it. They can see they are getting to you, STILL - after all these years.
Show them they mean nothing to you and you have better things to do with your life than step in dog shit. Just ignore them, Trev.
If anyone makes an effort to break in, that's trespassing - call the police.
And keep talking bro. Don't worry how it comes out. Just say it all. We are all on your side.
Nobody living can ever stop me
As I go walking my freedom highway.
Nobody living can make me turn back:
This land was made for you and me. (Woody Guthrie)