Drummerswife, please accept my heartfelt and deepest condolences, a difficult event at any time and this is certainly not the best time of year. Firstly, take a very long and deep breath, I don't feel any need to make immediate decisions and it certainly wouldn't be wise to do so. Perhaps some practical help is needed here to help with making your next steps. You don't mention any children, do you have any and are they adult age? If so their support will be valuable. What about your hubby's side of the family, anyone there you can call upon for support? As for the house there may not be any need to change anything but if you have not already done so I would contact your mortgage provider as soon as possible to advise them of your circumstances, at least you're being reasonable and they can probably help you with making important financial decisions.
I've trawled through the web for some useful points of contact. You've already got the suggestion of visiting your local Citizens Advice Bureau, I would follow that up as soon as you feel able to as they will be very sympathetic and helpful.
You don't mention your age but there is a service for younger widows - The Way Foundation - link for their website is: http://www.wayfoundation.org.uk/
Another service is this one: http://www.nawidows.org.uk/
CRUSE are a voluntary organisation to help with bereavement, I found them very helpful when my brother died and they can support practically and emotionally. Check your telephone directory for a local group, they work on a voluntary basis so you may need to leave a message for a call back. Link to their website is: http://www.crusebereavementcare.org.uk/
And there is always the Samaritans for a confidential chat at any time when you need a friendly voice to speak to.
I sincerely wish you the very best with the way forward, please let us know how you are getting on, don't feel you need to make any decisions alone and there is always someone on this forum who is happy to chat. xx