I've been severly depressed lately and don't know what to do..?

my grades have dropped a full letter grade as of lately because I'm feeling so lowly that I don't see the point of doing the work. I can never have free time to do things with my friends because I'm a caregiver for an ill family member. I've cut for about 4 years and stopped and have contemplated suicide many times. I am afraid to go to the doctor or the guidance counselor because I don't want to end up in a psych ward but I don't know what to do. I feel like crying all the time or just staying in bed and I end up bursting into tears. I feel like there is no hope for me and I just don't know what to do because if I tell someone then everyone (family, teachers, friends) will look at me differently. I need advice on what to do because I don't think I can deal with feeling this way for much longer because it's been 4 years! help.