Could stress be the reason i can't get pregnant again?

Probably not: I see that you are 41 and that is probably playing a much larger role in your secondary infertility than stress. At your current age, you probably have 1 out of 40 to 50 eggs that are normal. You might need to check the following checked: hormone levels on cycle day # 2 or 3, mid-luteal Progesterone test on cycle day # 20-22, hysterosalpingogram, hysteroscopy.