Heard Dave Liebman talking at a college near me. He said that every student of music should go 3 months and practice atleast 8 hours a day sometime in their life, and to make it their life. Wake up, eat, play, eat, sleep, wake up....
Now although he said not to do this while your jamming with people ( i think he was talking about strictly a technical workout), practicing that much and playing with people that are much better than you, man, don't complain!
Aslong as your not f***ing around on the set and actually practicing, you should get a whole lot better, and your 19, this is the time for this! You don't want to be practicing 1 hour a day, and look back in a few years and say what if I had....blah blah blah you know? I plan on doing the same thing in a few weeks when i finish school, you know, the three month thing, and set out a schedule
All the best woth the practice! You seem like a smart devoted guy, I don't see how you might see a problem with this! You are trying to make a living out of this yes?