Hi Ailsa, welcome. I'm 42, with a 2 yr old and a near 5 yr old. SOrry so brief, I can hear them waking downstairs ....
When you have your next OH appt, ask for an ergonomic assessment. They should follow you around your typical activities and look at how they could help with aids or advice. Maybe lowering a white board, giving you a teaching assistant, changing store cupbaord handles (I'm improvising wildly here, sorry)
At home, if you haven't already, and assuming you are in quite a great deal of pain (Tramacet to deal with pain at night) GIVE UP HOUSEWORK. Seriously. Parcel it out to family and cleaners. It was wearing me out and down, as no matter how much I did I never got on top of it. I still do a fair amount, don't get me wrong, but our cleaners do a 6 hour sweep every week - it is high quality and thorough and doesn't wreck my joints or take my energy away for the day.
Of course, we struggle to have holidays, paying out London cleaner prices, but hey-ho. Needs must. Good luck! xfx