When can I say no?

I’m ECT 2 in a reception/Y1 and Y2 class. Last year I was reception/Y1. I love my school. SLT are generally pretty great/don’t put any big pressure on me and I have no complaints at my school.

But fuck me I’m doing so much. Everything I’m doing I NEED to do (lesson planning/EYFS provision, send plans, assessments, phonics organisation etc…) but it’s all taking so long. I’m working so much and even though it doesn’t sound like much when I write it down I’m 1 person doing 3 people’s job. The amount of time I need to spend on my lessons to stretch my basically non-blending year 1 and stretch my insanely high attaining year 2s is so long. Each morning I teach phonics, y2 literacy, reception mastering number, y1 maths and y2 maths. How can that even work? I get the ‘do y1 input send them off do year 2 input’ but they all need support. They’d also need to be quiet while I’m doing the other inputs. Doesn’t sound like a nice classroom to ‘voices off and do your maths’. I have 2 TAs (one for reception and one to support) but I still don’t see how it can work? Any suggestions would be greatly appreciated. I think I’m a pretty good teacher and I make good choices and organise my kids well. I’m good with behaviour management and my lot respect me. I just need a way to make this work.