21 years old and looking for advice on how to tell my anti-gay parents that I'm moving out soon (Crosspost from r/advice)

Made this throwaway to seek advice, will probably delete this after a bit.So I'm a 21 year old guy and I came out as gay to my parents around the time I turned 19. Their reaction was pretty awful. There were a lot of tears and a lot of anger. They made accusations that I was going to be responsible for ending their marriage, for my brothers potentially being bullied about me being gay, for my grandparents literally dying if they ever found out. They said it was like a death in the family and implored me to go out with/marry girls anyway ("we know someone that definitely is [gay] and she's takes care of him, she's like his mother" gr8 sales pitch guys). They told me that I wasn't living in reality and had to return to "their" reality and that I was ruining my chances of having a career. They were furious at me for telling my friends before them and my dad made it clear that he'd never come to my wedding or have a part in my childrens' lives. They also forbid me from telling anyone else [which I ignored] and forbid me from seeing any guys while I live in their home, saying that I'd bring diseases home and infect my brothers. For a while after this they were extremely suspicious with regard to my whereabouts at all times and accused me of keeping secrets (i.e. having a secret boyfriend, which I didn't). All of this was pretty traumatic and I was in counselling with a local youth health centre for about 8 months.Fast forward two years and it still troubles me and makes me doubt myself sometimes, but I've mostly gotten over it. It hasn't been brought up since I came out to them, but I feel like it's become the elephant that's always in the room. I don't want to live here anymore because it hurts living with family that doesn't support me that way and it really galls me that I can't have a boyfriend or even go on dates without extreme paranoia that my parents will somehow find out. I've hooked up with guys on the downlow but that really isn't enough for me. I need a relationship to be on the cards and I really can't wait until my mid-to-late 20s for that to be a possibility. As a result I've decided to move in with some friends in September. The place is totally sorted, deposit down and all, and I have a permanent, steady job that I can support myself with.My problem is how I go about telling them. The prospect of me moving out has come up before: when I got into arguments with my dad (past tense because I don't really speak to him at all anymore) he often reminded me of where the door is and one time he very seriously advised me to move out because I "clearly don't respect the rules of the house so I should find somewhere else". However, when I took his advice and told him I was looking to find a place he got very defensive and offended, asking me whether I really hated them that much that I was trying to get away from them and that I'd break my mother's heart if I told her. He also mentioned that I should "do what everyone does" and stay here until marriage which set alarm bells off in my head - plus he wouldn't even recognise my marriage anyway? But I digress. That was about a year ago. As a result of this weird hot/cold dynamic, when I was going about getting this place for myself I decided to do so in secret, without involving them until I had all my ducks in a row and knew exactly what I was doing. The problem is that I've crossed all the Is and dotted every last T by now but I'm just really scared to tell them. I know they're going to react really badly and be hurt that I didn't tell them. Additionally, I would ideally hope for them to keep paying for college as I'm starting my Masters degree in September. I would of course pay them back for this in monthly instalments as I have done for my undergrad degree, but if they say no I'll have to get a loan from the credit union, which would be fine but would be more difficult to pay back in addition to rent. The loan is within my means but would just be a bit more difficult and would leave me with less money per month compared to paying back my parents.Anyway, apologies for rambling, but I'd really appreciate any advice on how to go about telling them while keeping on relatively good terms. I know they're going to take this really personally (which tbf they should because they're the ones that drove me to this) and I can just tell it's going to be an awful conversation. I think they want to keep me here so they can keep an eye on me and make sure I don't have a boyfriend. The last time I told them something big really big their reaction really damaged my mental health so I'm very concerned. At the same time I know I have to tell them soon because I'm feeling very anxious about it; I keep waking up in the middle of the night thinking about it and having bad dreams, and it plays on my mind all day.How do I tell them in the most diplomatic way possible to minimise their freakout?(Thanks for reading that word vomit btw)