Hello and thanks for writing to us. My name is ***** ***** I'd like to help. I am sorry you are feeling so depressed following this loss and I am sorry for the loss in general. Death that is close to us can bring about all kinds of complicated emotions. Often, loss can be bittersweet where there can be some appreciation that the person who died is free from pain but it also can leave us with a hole or mulling over the processing of life and death and how it relates to our own lives. Being as you were so connected to this loss and the aftermath, it is absolutely possible and even likely that you will also have to grieve which is the natural processing of the host of emotions that accompany a loss. That would be totally normal and expected.
Also, it sounds like you were very consumed by this death with making the arrangements and doing the work of clearing the apartment so more than likely, you are just plain exhausted and need to get some good rest. Was there even travel involved? Not only is death and loss hard on us emotionally, but the logistics of it can take their toll as well. So give yourself the break your body and mind needs right now. Attend to taking great care of yourself through good sleep, healthy eating, and exercise. And then, treat yourself to something you really enjoy once you get your energy back.
If these feelings of depression have not faded within a couple of weeks, it is possible that you will develop a more "clinical" depression and need treatment through this. Major life event and stress can sometimes overtake our minds and cause depression so even if you have never faced this in the past, it could be a factor. In that case, call your doctor and tell them how you are feeling. Then the two of you can come up with a plan to manage this - ideally involving medications and/or counseling.
I hope this helps! Please rest assured that your feelings of depression following this would be considered normal grief following a death and are likely confounded by all the time and energy you put into honoring this person. That was exceptionally kind of you - you must have a really huge heart. Sometimes those huge hearts are more susceptible to pain. So ride out these emotions for a few days, allowing yourself to feel them is all part of the healing process. You'll get through this and come out okay :). i am sorry for your loss.