Was this wrong of me?

hey :) At the minute i am working in Sportsdirect and Argos and recently quit my job in the out of school care due to the fact I possibly couldnt manage the 3 jobs and had fainted a few times in work because i was not getting time to eat between each job! i also felt like I had no life tbh! I tried to explain this to my manager at the after school care but her reply was " Well i work full days, you will have to do your 4 weeks notice". I agreed to it at this point as she was really intimidating but after I got home i had a think about it and phoned her to say i wouldnt be back. I never signed any contract, do you think this was wrong of me, feeling quite guilty at the moment :/ Do you think i will get paid for the hours i worked before i quit? thanks for your help.