I feel like this a lot, mainly because I'm shy and haven't got any friends. I also feel that I cannot talk to my family, I don't feel close to anyone.
How I get through it is to remind myself that I am not alone in how I feel. Lots of people feel lonely all the time. Some come on sites like this, others join clubs and activity groups.
One thing you need to realise is, people do care even if you think they don't. I was depressed for several years and believed that there wasn't anyone that cared about me, but they did and do still. It is low self-esteem that made me think what I did. There are ways to overcome it, look on Google or other search engines and you will find lots of stuff about it.
On a side note, it seems that us lonely people have our ancestors to blame