need some advice

I have been really struggling lately with money and jobs.. I’m currently looking for other options and been getting some calls for interviews, my job at the moment is a crap 6 hour a week contract it’s the only one I could find and I’ve been stuck here for 2 years, I get overtime sometimes but not recently, I’ve been thinking about just quitting to focus on my jobs search as when I get interviews I have to work it around my job I have now for example this morning I had a interview at half 9 and my manger called me at 9 to say she has been called into another store for 2 hours and I have to cover and I feel like I’m having to give up certain interviews to keep this crap job.. I have some savings to tide me over but I just really need some advice.