PTSD?

[guilty670]

I am eighteen and my family has a history of depression (my mother had severe postnatal depression, among other things). I went through moderate depression during my early teen years (I was perhaps thirteen or fourteen) but it was more situational than anything, as my grandfather had died, I was being bullied and my mother broke up with her partner of two years. I am an only child, and at the age of 3 my parents broke up. My father and I do not speak anymore, more a simple loss of communication than any real blowout. I do feel I rely way too much on my best friend to keep me happy, and I am sometimes very upset for no reason at all. I do not cry very often, if at all. I have had an anger problem before (also picked up from mum, who is very stressed as a person) but have since (I think) reigned it in.
However, I think I may have Post Traumatic Stress Disorder, due to someone very close to me sexually abusing me twice as a teen. Is this a possibility and if so, do I need to see someone for it?

[capegirlnoshoes]

Quite possibly.  You could also be mildly depressed.  And even if there's nothing clinically wrong with you (quite possible) and this is all just normal aftermath from some bad situational stuff, going to some counselling sounds like a good idea for you.  But make sure it's with someone qualified in Cognitive Behavioural Therapy, because there are some VERY rubbish counsellors out there.  CBT is very useful indeed, just for coping with ordinary life issues as well as with clinical disorders.  
Although you may find that you know all the CBT stuff instinctively, as some people with troubled childhoods do (like me).  
Don't let them give you any medication unless you know that you can't function without some kind of chemical help.  Young people like you and me with mood problems can develop bipolar disorder if given antidepressants when they don't need them, and some doctors are a bit drug-happy.  

[mammo]

Absolutely!  It is things like this that are often the cause for one to be experiencing depression and/or anxiety.  Therapy would be very beneficial for you!  Your anger may very well be the result of all you've endured and therapy can also help with this.  You sound very level headed....good for you!  I do wish you all the best and take care!