I've felt this way lots of times too. it's just part of dealing with depression and i know it sucks. I think people sometimes, most of the time don't know what to say to someone they realize might be depressed. wish it wasn't that way but it is and if it is someone you think you might feel comfortable talking to about you may have to let them know "he i have been depressed lately" and see what they say, they might be going through the same thing to or did in the past and you might have a new person to be able to relate to, you never know.
Just know that you are not alone on here, there are lots of people even not on here but ones around you that feel as you do.
Even though it's hard most of the time, Just speak up about how you feel to someone you know, sometimes thats all it takes to feel better.