@missriss91,
Don't even try to do 30 vol on your own.
Go to the salon, get a good haircut that gets as close to the regrowth as possible.
I've been going from a deep auburn back to my once natural dark blonde - with the plan to have my hair grey with brightly coloured hilites. It's been an eight month process so far - having my hair professionally coloured every 5 - 6 weeks - having it go slightly lighter and less red each time. In effect, they are dyeing it to match the faded ends each time. I also have had close to a foot of hair cut off so far this year.
You could have gone with the low/slow approach but by getting in there yourself you've pretty much set yourself up with a serious haircut being the only option that will end up with hair worth saving.