It is quite common to have such depression
after major surgeries. In fact I passed through that stage twice. One at 47 years old in 1990 and again at 58 in 2002, when I have CABG heart surgeries twice. It used to be very horrible and I used to get agitated due to healing of micro fractures
occurred when opening the chest and palpitation
normalization after surgery. But all should subside in 4 to 6 weeks time and you should be able to resume your normal duty with prescribed medication, etc. Patients who are depressed one month after undergoing bypass surgery
are more likely to have chest pain
and other cardiac problems five years after the surgery.
So it is very essential you should try to get to relaxation technics and be active and cheerful. Your doctor and the hospital could have advised you in this regards. Just do not brood over the happening or the expenses etc. and spend time in the manner you like and you will be alright very soon. Best of luck.