is it worth to keep this going?

started a new job, but they’ve began to start scheduling me only 10-15 hours a week. some weeks are special where i can get up to 20 but that’s rare. i was ensured close to 40 hours a week because it’s a high traffic mall and a successful store in the company across the US. it is summer, i don’t understanding why i’m getting scheduled less and less. some other coworkers are experiencing this because they just hired 10+ new employees instead of giving enough hours to people who have already been working here. not only that but i only get paid $15/hour so my paychecks are usually weekly around only $150…it’s not sustainable at all. do i see what the next 2 weeks of my schedule look like and put in my 2 weeks to look for a different job? my manager also had a horrible attitude but i can tolerate that, it’s me not being able to afford to live that’s scaring me.