Lower confidence level. Or psychiatrist.

I believed that i am a talented person and was good at presentation skills, till the time I joined mba.I have a habit of getting easily influenced by people. Two of my classmates who don't like me, always keep on discouraging me. They made me convince myself I am not good at anything. I am really not able to deliver a proper presentation now. At the time of presentation I started stammering, feeling I dont know anything. I joined MBA because I wanted to get a good placement. But now I am afraid of even attending interview. I didn't shared this to anyone, feeling they will laugh at me. But I can't carry this burden anymore. I feel like my career is getting destroyed. There was a time when suicidal thoughts came to my mind and i am not even able to sleep properly. I somehow distracted myself from that thoughts. I need a help. Should I consult any psychologist or psychiatrist.