But 40/10 would give you exactly what you have now.
Yes, that's what I thought. I'd drop to 40/10 quite happily.
I was being frivolous when perhaps I shouldn't - the last few days have seen me pulling out what little hair I've still got and then laughing and crying in turn. I don't want to tempt fate but last night and this morning things seemed to be improving and enabling QOS on my router seems to be having a calming effect as well. Fingers crossed!