Look into R+D. I was in the same boat as you. Then I decided to take a look at research, now can't get enough of it. There are government funding for PhD's (Search Department of Education and learning (DEL) Funding.)
I'm British and went from industry back to do a PhD at 25. You don't even need to worry yourself about searching for funding - there is plenty available for CS and I found it was enough to live on even though I'd been used to a grown-up salary.
I'm considering something similar (23 now, studied in Imperial, working now in the US, but missing learning so many new things like I had in undergrad).
Did you experience a large decrease in quality of life? Have you saved up a lot until you started at 25?
I managed to live off the stipend without too much of a problem - but I lived with my wife and she paid the mortgage while I was studying so I suppose I didn't have any accommodation expenses. In my second year I did a six-month internship in the US and came home with a five figure sum which made it a lot easier.