Long story alert but am I overreacting?

So I am 21 years old . I have a 16 year old sister and I do not live with my parents I live in another town about an hour away. I have had my driving permit for almost 2 years now (I got it when I was 19 I know I’m a late bloomer) but I don’t have my license. I was due to have my license test in March but I’m not ready for it at all. My parents never taught me how to drive and still refuse to help me. Well my dad does offer but he yells in my ear when I do something wrong because he’s a very anxious person and overreacts. I have my own car that I paid for myself as does my sister. I was told I can’t be on the insurance but my sister is on my parents insurance. So there’s no way for me to drive my car and you can’t get insurance without a license. Yet my sister has been driving a lot more than me with my parents since she lives with them and almost has her license she’s taking the test in April. Long story short it just pisses me off that I’m 5 years older than her, have had my permit for longer yet I’m not the priority? Yes I understand im an adult but I’m still my parents’ child. I just hate my family sometimes. And I can’t take drivers ed because I can’t afford it and it’s around $400. It just makes me angry they never prioritized me even though I’ve had my permit for almost 2 years and I have no one else to teach me. And how would you go about getting your license. I wish they had drivers Ed programs for low income people.