I want to come out but I really just am so unsure, can someone please help?

Hi. Sorry, I don’t know if this is the kind of post that’s meant to go here or not. But I figured it’s the most appropriate place. So, I’m 17, male, Australian and I know I’m gay (of course). My friends and other people from high school (graduated like 2 months ago 🙌) know and are fine with it but none of my family except for my half-sister have any idea (as far as I know). I kinda have a lot of questions and I hope there are some answers. I’m just going to start haha.So I really feel like I need to come out to my mother. I live with her (just us) and I just feel like i’m always having to hide myself and who I am. My sexuality but also parts of my personality to. She’s fine with gay people and everything out in the world, as much as any other typical gen X woman. But, it’s not as simple as that when it comes to me. When I was about 15 I did actually come out to her after she found out I reblogged a gif of two guys kissing (it was so wholesome it was literally a peck) on my tumblr (which I deleted my whole account at her request and never looked back). I told her I was and it was so crazy for me. I thought she was so accepting of it all but she just got, angry I guess and sad, and said she felt alone and she didn’t know how to process it and that she doesn’t think I am and not to set it in stone. By the end of the week I was considered straight. She acted like it never happened. So I don’t know how to tell her again. I don’t know why I should have to come out again and I don’t know how to do it. I think I could deal with whatever outcome I just can’t bring myself to do it. I don’t know how she’ll react. What should I do? I just want it over with. But with the whole yes vote thing and she was all for yes with it vocally I felt more confident to tell her. But then the way she reacted when I wanted a bike helmet that had pink on it was just so weird. She acted shocked and acted like I shouldn’t get it, it would be weird. So i don’t know what to do.I want to know if it’s appropriate to tell someone you’re gay over message? I have a half brother who I really hope would be cool with it that I never get to see. We aren’t that close but we’re definitely alike and I want to be so much closer to him but I’m afraid this will make him think I’m weird or not good. If you know what I mean. He’s around 24 and on the off chance we got to be together there’s no way I would be able to say it out loud. I hate saying the word gay to be honest. I’m content with being gay (to a large extent) I just don’t like saying it. In that situation would it be acceptable to tell him over message?If I told my mum does she go around and tell the family or do I have to keep going down the line? That would be horrific everyone else in my family are traditional macho Europeans for the most part. That would be so scary. And my dad (who I don’t know very well) would totally hate that I’m gay I know that. He thinks it’s totally gross. But when he was younger he was fine with it. It’s so weird.I’m sorry this is so long. One last question. Would it be appropriate to message my mum to tell her? If I was maybe at a friend’s house and messaged her so if it was bad I wouldn’t have to be with her for it and she could process it on her own? Or if I was even in the house with her and I messaged her? I just don’t know if I could say it out loud to her after last time. I hate it. I hate saying ‘I’m gay’ out loud. It makes me so uncomfortable. And I’m so scared someone will ask ‘but how do you know?’ Because mum asked me that when I told her the first time and it made me want to die. I just like guys but I couldn’t explain why and who wants to talk about sexual attraction with their mother?Anyway, if anyone has anything please tell me. I’m sorry this was so long. Thanks in advance. And sorry if this was annoying.P.S Also real quick question what’s being gay like in university? I’m really curious and would love to meet other members of the LGBT+ community and even find a boyfriend (that would be so amazing). So what's it like? Or maybe that's for another post. Anyway. The ball's in your court reddit 😊. Please help me out 🙏👏🙌