I'm not sure how to get needles

If you have access to amazon, you can get both needles and syringes off of there without a prescription. A search for 25-gauge needles and 1ml syringes gave multiple results, with amazon even providing the other item in the "frequently bought with" section. Amazon also tends to have delivery windows you could watch out for, as well as options to delay the delivery to days that might be more convenient for you. I guess that would be my advice on the estradiol front as well, make sure you, or whoever is getting it for you, is tracking the packages so that you have a way to view when it will show up (again, to prepare).

being stupid about family saying shit

I'm almost 8 months in, and even now it would be really easy to hide. Large hoodies and sweaters are too baggy for anything to show through, and in general baggy clothing is going to be your friend. Even then, it takes a bit for physical things to start happening. It took almost a month for me to start feeling breast growth, for example, and it took even longer to show through a tight shirt.

I'm shit, very privileged and should already have it.

You shouldn't already have it, because you haven't gotten it yet, supposed privilege doesn't always play a role in how easy it is to start HRT. You are still working towards it, and finding out how exactly you could make it work. Your brain is putting up obstacles because they are reasonable things to worry about. Your family noticing things is a valid concern. Not knowing how to get equipment is a valid concern. It's certainly not stupid to worry about those things, in fact it's pretty smart. A vial of estradiol wouldn't really help if you didn't have the proper equipment, right? I said it in my other comment, but being autistic, and having trouble changing, does not make you stupid or useless.

Please, take care of yourself, and don't beat yourself down, especially for being who you are. You are the only person like you, and that is something special in itself, because without being neurodivergent and trans, you would just be a completely different person, and that's not you.

It's reasonable to be scared and anxious, particularly what you've disclosed about your family before. Ultimately, what medication you want and need is your decision, not your family's - that doesn't mean they might not be shitty about it and maybe even a pain in the ass and do stuff like throw out your meds, but its always going to be your call what you want to put in your body. I don't know and can't guarantee how they'd take you being on HRT, but I've been eternally surprised by some very rural and very conservative parents taking their kids transition in stride (because they might not get it but they love their kid). This doesn't erase some of the horrible things that still happen or your anxieties.

You've been dealing with a lot of very hard emotional things lately. I know it can feel overwhelming. What are some things you think you can do to get past any shitty family behaviour? One possibility is keeping your medication and needles with a friend you trust, do you have any what I'm gonna call "bonus parents"? Like parents' friends you can trust and be out with. Do you have any ideas?

As for how to get needles, it depends on where you live but usually you're able to purchase medical supplies online. Sometimes you can get it with no questions or prescription from a pharmacy, depends on where you're at. I requisition my supply from my workplace lol~ If you get needles, you can get a sharps container for them and should (usually pharmacies supply them sometimes for free and will dispose of your sharps when it's full and get you another rbin).