I'm having a dilemma about my subject choices for next year so any comments would be really helpful.

Currently i've put:
4U maths
2U eng
Eco
Chem
3U music

So that's 13 units altogether and i feel like that's going to be alot like workload and time wise. So i was thinking whether I should drop music and continue ext eng or continue with 13 units or do 2u music and ext eng and drop it later???? I would really prefer 11 or 12 units but idkkkk.

In terms of my abilities, I'm ranked pretty good in english and my school is one of the top 10 schools in english. For music I play piano and I'm currently doing lmus but i mean if i dropped music, i would probs just quit piano hahaha? yeah idk. pls help.