Is it normal to feel physically exhausted right after a hard break-up?

The break-up happened on the 2nd of Jan. I really did love her and as much as I try to push forward, I feel that I need time to grieve. I’m just so tired, though, physically. It could be depression, or just that the last month has been horrible in dealing with the relationship, and now the break-up, and all of it has finally caught up to me.

I have all intention of getting out there and enjoying myself, eventually (hobbies, going out with friends), and, have thought about talking to a counsellor, but, right now, I don’t have the energy.

Has this ever happened to anyone else?