Stress And Depression

Hello, I'm 21 and 3 months pregnant. This is my first baby. I know the first trimester is very critical for the development of my baby but I've been really stressed and depressed since the very beginning of my pregnancy. It's because I feel like a failure for being pregnant this early. My family was really disappointed with me but eventually accepted the baby and supports me since I still don't have a job but I already graduated last April this year. Sometimes, I can't help to be depressed because my pregnancy was very sudden and I feel like I won't be successful because of what happened to me ? I also don't want to feel this way since it will affect my baby. I need some advices mommies. Thank you.