I've been feeling scared and sad all the time. I don't know what to. Help?

Ever since i graduated from High School I've been feeling angst and fear. I don't know how to deal with it or what to do about it. I want to cry all the time but cant find the will to cry. Maybe because it wont solve anything. Sometimes i feel happy and at other times i feel so sad that i shut my self off from everyone and everything and torment my self in my depression and sadness. I think im like this due to the fact that i don't know what to do with my life. Going into college started all this to me. First of all because i cant seem to decided what I want to do with my life even though i have declared a major. Every time that i go and look up and research my major i end up finding negative and positive information about it. So its 50 50. My parents always put me in this big pedestal and expect me to be this big person in life and be successful. Okay im with them on that but its so much pressure on me and expectations that im about to explode and just drop everything and leave. I have no outlets. Expect for my job which takes my mind off of it but only for a while. I literally stumble through life and don't know what i want. Currently im majoring in Communications with a emphasis on Public Relations and i think that's a pretty good career to go into, but in from my research I see that its 50 50. At the same time i think i cant do it because it seems in just going to school just to go to school and it seems im not getting nothing out of it. That makes me so angry with my self. Also, I want to tranfer to a four year colleg ebut that is so out of the window right nowcause i have to finish my genreal ed and transfer courses to move to the four year college i want to. Im already registered for classes next semester but i dont know if i want to keep moving in.... even though i know i must. I want to change my major but why would i throw away what i already got and start over with something new and besides i suck at math and science. That makes no sense and it would be a waste of time and money. Sigh... i guess u have to stick with this. Even though I talke to alot of my friends about and and family they seems to help alot and make me feel better but there i cant seem to ge trid of this angst and feeling of fear. My depression had led me to almost doing crazy things that will put my life at risk and die. But looking at it i dont want to because i know i can succeed but then i lower myself down and see that I cant because of how im feeling..... Im very blessed that my parents love me and havent kicked me out of the house and have a roof to live in.im just very scared at times because i dont know if i want to continue doing what im doing or just stop living in general. im very scared of life and moving on. Im tired of crying and putting myself self down all the damn time. I have no reasin for it but i guess im doing it for a reason for which i would like to know. in the end i think its my career path that has me with all these doubts and my fear and depression. i also think so because all my classes for my major i think they are fun and very enriching for my career but i feel like they are not suited for me. what do i know im a nobody.... finally i dont htink i can stand and feel tthe pressure of my parents wanting me to be something important and placing me in a very high pedestal... it tears me up inside feeling that like i have to do something about it to stop it... sigh..... any psychological help and advice would be appreciated. thanks........