Help feeling down and confused?

wonder if anyone could help. The last couple of weeks i have been feeling down stressed with work and college and loads of fears. When i was younger i had a fear of wetting myself stupid it may seem but it felt so real. feeling as depressed as ever i have had loads of thoughts in my mind which are driving me crazy and just can't take anymore. I feel like my mind is playing tricks on me with things a felt so horrible about like pedophila, murder,rape and even incest. I could be walking by someone and just say what if i was to hurt them ect. Its relly getting me down cause i have been saying to myself i am not a bad person ect but just cant seem to trust myself its horrible. I dabbled abit into psycology at college and feel like i have a fear of the mind ect and how people act and how people can just flip and be killers ect. I have never ever thought about suicide as i thought it was wrong. any help would be preciated as im at whit ends and feel so alone sorry if this seems depressive.