Is something wrong with me?

I'm 13, I have a bunch of friends that I've been with for many (7-8) years, even though I've been with them for that much time, I still sometimes feel like a stranger and I find it hard to talk with more than 4 of my friends at a time, no matter how close they are to me, also when I'm talking with only one person the "awkwardness" goes away, its just when I'm with more than one other person, normally I just sit and read like 15-25 feet away from everyone, I sometimes feel randomly depressed and I don't know what to do about it, I've been through counseling for awhile after my dad left when I was 6, but that didn't help, and there have not been many (bad) significant events since then, I also wonder if its the fact that my dad left that causes me to be like this now.