Job help

Hiya so I'm currently only 15 however I got myself a job at an ice cream shop to earn money. I go to school 5 days a week and then on the weekends I wake up early and go to work at this place for two hours (wasting money on taxis there and back) to only get embarrassed and to get treaten with less respect than everyone else because I litter pick and clean the animals out. 
However I got offered a new job at the chippy near by and it is good that is closer however the hours include me working 4-9 on school days as well and I only just get home at 3:30pm on a school day.
I don't know what to do as I would like the money so I'm able to buy myself stuff without depending on parents but I feel like I'm putting too much stress on myself? Help please!!