yeah, since from what you mentioned it seems like a recent phenomenon, I agree with what some of the others have mentioned about it just being temporary and related to your brother's death
one of the worst things you can do is obsess about not sleeping, so if reading a boring book doesn't help, I'd say just accept that it'll be a temporary thing and go with the flow
my only suggestion is to go through your entire bedtime ritual but instead of going to bed, find a comfy chair or sofa and read or watch mindless television - in other words, not something you'll get absorbed in - and if you end up falling asleep and spending the night on the sofa, so be it. at least you're sleeping.