When we wake up to the reality of life and death outside the organisation we can feel loss more profoundly. As witnesses we are distanced from grief because death is presented as temporary. Outside death can appear a greater loss than before and be more crushing at first because we have never learnt how to process this emotion. It is particularly hard when we loose someone close to us.
It may be that what you need regarding both your emotional loss and your divorce is some professional advice and support. If you seek legal advice for settling the divorce it means that a fair and amicable agreement can be worked out that is in the best interests of you both. They will be able to look at the bigger picture unobstructed by guilt and emotion.
You may also benefit from grief counselling since these emotions although not completely new are being approached differently and need to be processed differently. Having a supportive third party who can help you navigate these strong feelings may be helpful.