I always try not to spend too long in bed sitting up because it's just too soft and tricky to get right....my back and neck always end up aching (I have degenerative problems in my cervical and lumbar spine).

The best I can do is to wear a shawl or warm soft scarf to keep my neck warm, and to use at least 3 pillows behind me - a good solid one in my lumbar area, and two behind my middle and upper back. That keeps me pretty upright. The other trick is not to do anything (ie typing lol ) that means your neck is bent forward for long periods as that's a killer and can take days for me to get over!

If I'm going to be there a while I also try to support my head behind with a pillow, as that seems to help. If your mattress is very soft then it might just not be possible to do - sitting on a really soft surface inevitably curves your spine if you're not constantly straining to keep straight. Ouch.

If I'm feeling in need of cosiness, I prefer to spread a warm blanket over my sofa, and have another to go over me. Then I'm in a better position for my back, but still warm and supported. Plus as a bonus, going to bed later on is a change of scene!

Good luck and I hope you find a way that suits you.

Bram.