Would this PTSD?

The day after I went to my grandmas funeral (which was the first funeral I had ever been to) I was in a very mild car accident the day after her funeral, someone just backed into us, after my grandmas funeral I started to get insomnia and having REALLY bad nightmares. Then a month later i got into another car accident, neither of which I was the driver, and that time I had to go to the hospital in an ambulance. Ever since then every time I get into a car I get afraid of being in another car accident and If someone takes a quick turn I get flash backs of the accident. Since the second car accident I have had a lot of problems sleeping and anytime I get any deep sleep I have really weird and/or nightmares. Is this PTSD or something else?

Also can hitting your head really hard (flying into the windsheild) cause you to get depression or anything like that?

thats definitely PTSD.
you don't get depression from hitting your head if you have it its from the stuff you've been through. depression is a change in your brain's chemistry just because you're sad about your grandma and the accidents doesn't mean you have depression. sleeplessness can make you tired but its not the same as depression. if you see a doctor make sure you mention all the things you're going through because they may jump to depression even though you're only tired, sad, and have PTSD. anti-depressants will not help unless your brain chemistry is off. hitting your head can be a cause of your sleep problems, including headaches, blurred vision, etc.
i went to a mental hospital for a while and i have found that the only thing about it that helped me was the sleep i got, none of the meds helped me. in fact i became manic on the anti depressants they gave me. i had to get another drug to get me back to normal.

GO SEE A THEREPIST!

Yes hun it sounds like it because post tramatic stress disorder is when a something big happens to you in your life and is like scars you. Everything reminds you of it your dream about it and being in certain situation make you think about or even being around certain people or seeing certain objects. You think about it all the time. Because I had it and still suffer from it I never got diagnosed with it because it cause other problems and got more servere deffinitly get treated because it will form into something more servere like now i hace borderline personailty disorder. Yea think it can't get worse it can:( i seriously recommend treatment no im telling you to because iv'e been through so much hell I mean BAD !!!!! Don't let it get that far!!!! SERoisly listen to me because I suffer and it horrible i have sooo many problems its ridiculous. Just like if you get a cold and do nothin to treat it or take it easy or w/e its just gonna get worse !!!!!!!!!!! <3

To some extent these are normal reactions to a good scare. It depends on the severity and persistance whether to label it PTSD. For most people the symptoms will wear off after a while. The diagnostic manuals seem to say if they are still present at 6 months then it probably is PTSD.
Best treatment in my opinion EMDR (Eye Movement Desensitisation Reprocessing.) Lots of people would disagree with this and point you to Cognitive Behaviour Therapy.