You are in mourning. Go easy on yourself. Now is not the time to listen to your inner critic and judge yourself so harshly for not being where you think you should be. It is understandable that you are sensitive right now and in need of reassurance and TLC.
Yes, there may be deep-seated self-esteem issues that need to be addressed and all of that, but it has only been two weeks since you received devastating news and underwent a procedure which left you a bit traumatized. You've been through a lot, and it happened without warning. Find ways to be gentle and loving toward yourself and don't be afraid to ask your partner for some extra attention and kindness.