I want/have to move out in sept. i only make 450 every 2 weeks

alright, kinda complaining, kinda looking for advice.

I love my job, like LOVE my job. It's a tiny aquarium store, super well known in my area. super flexible, super chill, incredible coworkers, exciting to see new species come in every day and help people with their tank problems. im always excited to go to work and disappointed when im not there.

the issue is i only get 12.5 hours a week steady, because I was sorta an impromptu hire from my boss (i legit walked in oldtimey style and asked for a job and got an interview). I make 15 dollars an hour.
its not bad money for a college age kid who lives with their parents, its enough for me to have fun for the 2 weeks until my next paycheck, but im always left back at 0 by the time my next one comes around.

I have 0 savings. I want to save up to move out, because I'm hoping to get into SAIC in late august/september. If i don't get in, the timeline is more like january 2027.

I need more hours but I can't get them, there *isn't* more hours for me to get. my boss (who is a great, great dude) said he'll give me every second hes got to give me, but when someone isn't calling out, i get what i get.

I'm thinking about getting a second job, but I don't know how to do that without screwing up the balance i've created with this job, it's not evenly cut hours its kinda just all over the place.

I'm no longer going to spend a cent of my paychecks (with the exception of my girlfriend's healthcare needs. this is a big financial stressor but she hasnt been able to get a job, since she never had one in highschool the job market is awful to her). I'm gonna start living like I have no money to try and save up, but the math tells me i'll only have 4050 dollars by the time SAIC school year comes around and i know i'll have to spend *something* *somewhere* before that date.

Not really sure what to do here.