Should I seek Professional help?

I've been depressed before, but I have recently overcome it (or so I think). I am now more capable of having fund day to day and I stopped stressing about schoolwork, but now that schools out I've been having some problems. Last summer I spent a lot of time alone and it was very therapeutic for me, but its not having the same effects now. Sometimes when I am alone I have these like mini panic attacks or something. I sit in the middle of a room in the fetal position and just cry into a pillow (so that my family won't hear) for what seems like hours but is really only between 20 and 45 minutes and I feel like my world is collapsing on to me. I just get really scared that I'll never have fun, I'll just live at my parents house for the rest of my life, never go to college, no one will ever love me, I'll somehow remain a teenager forever, and my life will remain monotonous and the boring. This is really strange I think because logically this doesn't make sense. I have nearly straight A's and a 2200 SAT score. I just have this really strong want to be an adult and I don't know why because you're supposed to love being a kid. I just all of a sudden get really scared and I can't move and I just feel like screaming. Sometimes I feel theses attacks coming on and I get really scared and I've found that I can avoid them by immediately distracting myself. Is this a medical condition? Should I tell my parents (we're not that close so it would be awkward and they would probably say I'm being a drama queen and it would be weird. I once slipped in that I used to be depressed and they rolled their eyes)? Should I just wait this out like I did with depression? I don't know it seems that I don't really heal myself when I'm having symptoms of mental problems, it just turns to something else. When I was eight i starved my self,then attempted bulimia, and then just hated my self, then was happy, then became a control freak,then was happy, then was anti-social, then was depressed, then was happy, and now I'm 17 and this. Grr, I wish my brain would get it together, this is such a bother.