I lost my father under very similar circumstances. Only, it was June 4, he was 54 and I wasn't living home anymore. Especially if it's such a sudden death, probably with no signs beforehand whatsoever, the shock over it can sit very deep and it takes long to fade. I remember (if you can call it that, I only have vague memories of the months past that event) how it took me more than two months to get back to a state where my mind wasn't consumed with the loss. I had to do some finals in July, but I wasn't really able to prepare. I failed one and the others I just passed either because I didn't have to study for them, or because I spent a week with other friends watching them study, while sitting next to them not able to focus or concentrate. For some weird reason I still fared better than them in the end, because the things they studied stuck to my mind.
A good thing during this time then is to surround yourself with friends who can on the one hand distract you, but on the other hand be there and listen. If possible, it would also be helpful to make a short trip to get out of the place and have a change of walls. Especially since you are living directly in the place where all your memories of your father are connected with.
And then it's also never wrong, nor weak, nor anything, to consider professional help. As much as friends and relatives can be helpful, they can only do so much. A professional can listen to you in ways that others cannot, give you advice that others cannot and is distanced like no one else is. My mother would never have recovered weren't it for a professional helper.