I'm Feeling Depressed. I'm Like Always Frustrated. I Lose Temper

I'm feeling depressed. I'm like always frustrated. I lose temper very shortly. After some time I get confused that was I wrong or other was wrong. I really don't know that why I'm so frustrated but I'm upset and I'm scared to be a serious depression patient. Please help me. I'm just engaged to my boyfriend we are in relationship for 3 and half years but now I'm feeling frustrated I have fear in mind he is also always upset because of my this over reactions . No one understand me I'm feeling very confused