Wow, it sounds like your parents are really willing to listen to you!
My boyfriend has a similar dynamic going on with his parents, but they aren't embracing the change quite as much as yours.
Just remember, in the future, when they revert and put more pressure on you -- they're just being your parents. Moms like yours will
always nag you about what to wear to interviews. They consider it their rights as mothers. And a dad's interest in your career will
always feel like some sort of pressure you have to live up to, even though they don't mean it like that.
The thing that helped me with my parents, who aren't like that, was a combination of me letting go of wanting to make them proud, and them letting go of their need to parent me. It's funny, because once we let those things go, I do feel that I make them proud. And they do still get to parent me. (My mom loves feeding me when I come over, and my dad likes taking care of my car.) Those attachments, though, are what created all the stress in the first place.
I do know it's hard for my mom to stifle her mothering, though. A lot of the times, she call me maybe twice in a week, and apologize the second time, because she doesn't want to seem overbearing.
Which tickles me pink; I love talking to my mom.