One of my best horses has taken a turn for the worst! He is a 6 1/2 year old Tennesse Walker. He use to be the sweetest horse you could find! But in the past week he has bucked me off and even chased after me rearing and bucking, he is intolerant to cars as well. He use to be a type of horse that you could teach him to do ANYTHING and could take anywhere, now he is mean, intolerant, disobedient, and extremely antsy!! I am concerned for him! He doesn't seem like my stormy at all!!!! Please help! What could be wrong with him?