I feel so left out. Why do i feel this way?? am i completely hopeless?

I always feel not as good as anyone, not as clever, good looking, kind, talented, just a little bit of a failure. i feel like im not lovable and that no one values me, i feel un important and on the outside of everything, i find it really hard to form relationships and i never really connect to anyone. Yesterday i was with a group of people when they said they were meeting someone, they all rushed up to her and hugged her and said how much they loved her. i wonder why no one is that happy to see me, whats wrong with me. i don't think people are that interested in talking to me either, sometimes i feel invisible in life, im 20 years old and i do have a friend who i spend time with but fail to have a proper connection, people say im really kind and one of the nicest people they know. can someone help me. will i ever find a boyfriend or lover, i think i'll never connect with anyone. Everybody seems to be getting into relationships or getting involved with people, and i wonder why nobody likes me or is interested. I feel unlikeable.