Well, if you're the last child to fly the nest that'll be a big part of it. My sister is still at home, and pretty much buried under parental care... so yeah, there's a protective element and your folks knowing it'll be the end of an era and all that.

Sorry if I missed it above, but is it your mom's car you're taking to BK? If you've borrowed it 888 times before with no problem, maybe she's just a little PO'd at you for always having her car! :D Maybe think about getting a car?

Bottom line is probably as you say, if you can't support yourself yet you have to bend to their will to an extent. The way out is to have them come towards you - so you'll have to talk to them. Maybe give a little ground in exchange for more elsewhere - like you say, you're 20 years old - I'd been living on my own for 2 years by then and it's unrealistic to expect you to take on the role of a child at 20. Hopefully talking will produce some results - it also gives you an opportunity to demonstrate how 'grown up' you are... that'll help too.