If I take my life as an example... I studied in administration, I have a 9 to 5 job ( actually 8:30 to 5 but that's not the point lol ) that pays the bills and more.
Then one day I decided to teach what I had learn in my many years of guitar playing, that's when I found guitartricks. I saw an opportunity of actually teaching at my own rate, when my day job made it possible.
You see, my dream would have been to make a living off music... but I'm way to financially insecure to make that kinda jump. So I got a job that gives me the possibility of not caring about what I do in my spare time lol
So I can spend a full weekend making music, making lessons, going to jam with friends ... I don't have to worry because I have my day job.
The only advice I can give you is never forget that your day job makes it possible to do all the cool music stuff at work. So if at some point your day job gets screwed up because you over did it on the jammin ... that will compromise your liberty to do it for a long time. It's a question of balance, like any other thing in life.
Many times I been told I had no will to succeed by people at work, that I could really move up in the company because I had what it took but didn't put in the time to be successful ... that's when I make a cool little smile and say "maybe, but then again you don't know jack about creating a song ... does that make you unsuccessful as a person?"
You see, I do my job well. I do it to the best of my abilities and try to push myself once in a while to grow as a person, to push my own limits. I do this at work and I do it in music. I believe that what makes me happy in life. If I would be take a job that would take too much of my music I'd be miserable. You really have to find a balance and that will take some time.. maybe a few years.
Just try a few jobs when you get out of school, find the one that has more good side then bad, then work on balancing everything out.
And for the record, a lot of people that are not musician will get you man. They'll think you're blowing your life away .... but they are not musicians :)
I think you have the right approach of having a secure financial life and wanting to pursue your musical life to the fullest. I really hope you find that balance.