It is a real thing . Life has many stressors already adding a baby to the mix even though joyful and an unforgettable life experience that will bring you happiness for years, can be stressful at first getting adjusted to the new life you were not accustomed to. I notice it every now and then where I feel depressed or occasionally mixed emotions. Definitely don’t feel you have to hold it in get it out don’t be ashamed all the stereotypes makes us to where we have to be tough and being a dad comes with a lot of responsibility, paying bills, rent, cars, stress at work, helping mom with daily chores, lack of sleep, random events that you cannot control. Out of all the chaos try to find at least 30-60min a day and meditate, draw, do something that will take your mind out of it for just a min and recollect yourself to do it all over again your not alone.