I felt exactly like that before I found out what I wanted to do with my life. Now that I have a goal in life I feel a lot better. My classes don't start till next week and I can tell the difference when I get bored. Now I sort of want to do something relating to my career choice. I don't get that loneliness, or slightly depressed feeling either.
Try to find anything that will kill time. Recently I've been thinking about just walking around town.
>>2I would advise against using a substance, like weed or alcohol, to help ease the situation. That is how addicts become addicts. They replace the negative feelings, or situation, with substance. This never really gets rid of that depression, or stress, but replaces it momentarily.
Again, mainly find a goal in life and strive to get there.