Hello Esther,
So very sorry to hear about your husband. It must have been a terrible shock to you and your family.
Going back to work is very traumatic after any loss and feels very daunting. Do you have any support at work? I assume they know what has happened. Have they offered to let you go back on a phased return? If not, perhaps you should request this. It might help you cope a little better with going back, if you could ease yourself gently into going back, at first on reduced hours and gradually build them back up to your normal hours over time, that might make it easier for you. It might be worth speaking to your line manager and asking about this.
I recognise the feeling of not being able to get out of bed. This is a normal feeling when you are grieving and it is still early days and must all still be very raw for you. Do you have any other family to help support you? It might be worth it to go and see your GP. They could give you a sick certificate and sign you off work for a while and should also be able to give you information about grief counselling in case that might help you.
I am afraid grief is a very long and painful process and hard as it is believe now, it is true that it does get easier over time, although I would not expect that to be a short time. It is almost a year and half since my most recent loss and I still have bad days. I am not sure it is accurate to say that it gets 'easier'. It is more that you slowly come to accept what has happened and that this is your new reality and that in itself can take months. You learn to live with that, but it never does stop hurting, the pain just dulls a little and you get more used to it. The sadness never goes away, it just becomes part of you and surfaces at times and moves more into the background at others.
You are also feeling the added stress of now being a lone parent, so that must be affecting how you feel too and making worse the tangle of emotions you are going through. It can be quite cathartic and help you come to terms with what has happened to put together a photo album of favourite pictures of your husband and to write down your feelings each day in a journal. It really does help you feel better just to write them down. For the children it might be good to encourage them to do the same. You can get them to do this either in a book or on separate pieces of paper that they can put in a box or a jar, so that when they are missing their dad, they can pull one out at random to remind them of a happy event they experienced with their dad and this can help them feel closer to him.
You will find a way forward in time, but you are still at a very early stage and should not expect too much of yourself too quickly. It will take time to begin to recover and be able to face daily life again. You will never be the person you were and life will never be the same as it used to be, but you do gradually move forward and find your way into this new unwanted phase of your life. Be gentle with yourself and take it one day at a time. Just do whatever helps and try to get help to allow you time to do this. Things will improve in time. I know that is hard to believe at present, but they will, very slowly.
Sending you strength and a big hug, Esther.