I'm sorry you are grieving. Only you can decide about the pumping. Your DD is still so very new - try to go easy on yourself. Your emotions/hormones etc are all a bit messed up, and you know that you are lacking sleep as well. FWIW pumping is not as efficient as breastfeeding, so she is getting more than you can get yourself.
Please be gentle with yourself. What you have done so far is great. Better than never having tried at all.