Fear of moving vehicles after accident.

Met with 2 accidents within a span of year. In first case a car ran over me i had minor injuries only, second time a skidded bike hit me from back. In both cases accident was from behind. I dont have any bike or car so usually I walk to my office which is 1.2 kn apart. But after the second accident I am scared of each and every vehicle, my right leg moves automatically as without any control as if some vehicle had hit me, which was the case in my 2nd accident. I turn back a 100 times to look for any vehicle coming from back, otherwise I am always eaveswatching for the headlights of any vehicle. For every vehicle that passes by me scares me alot. Even the sounds like screeghing and honking scares alot even if it is far away from me