How do I overcome dysphoria and get a binder?

Hi, I’m non-binary and I have came out to my friends online, (i don’t have any friends in real life) and they were supportive and i’ve been trying to get to see my parents opinions on it because i am still not out to them. They know i’m a lesbian but they have no idea i’m non binary. They are overall supportive of that but my relationship with my mom ever since i came out as gay has been weird. I’ve mentioned non binary casually to her a few times and she thinks it’s stupid, made up, and that it’s just a trend. I recently told her I wanted to cut my hair short and she was very opposed. She asked me if i wanted it like a ‘boys haircut’ and I said yeah i guess so and she started crying. She later told me she’d cut my hair but she still had a hard time seeing me like this. She asked me when i wanted to cut my hair if I was trans and (technically yes) but then she went on to ask if i was a boy and I said no (bc i’m not) and I feel really uncomfortable about coming out to her especially now because of how she’s expressed her views. I really want to get a binder but I don’t know how i’d do that because there’s no way for me to buy one without them knowing and the dysphoria gets really bad sometimes. since i’m not out yet i get called she/her, daughter, and sister a lot and it really affects me as well as body dysphoria. I do not know what to do... :(