What Causes Abnormal And Aggressive Behaviour?

my husband has thyroid problems. if he does without thyroid meds or Prozac, he is like a crazy man. I believe he can be dangerous. I have never been scared of him. we have been married 46 years. I asked him how he could be so nice to other people but soon as he walks in the door I know here we go. the last time it was because I didn t feel like going with him to another church. he throwed a fit. another time we was driving down the road. he was driving. he started going side to side driving reckless. I said let me out. he said go ahead and jump. I hit at him, he must have had his elbow up. I hit with the side of my hand and broke my hand. I was crying and he laughed. if I had somewhere to go I would. I told him last time if it happened again I was leaving. he can take his meds. he acts like a different person. why is he like this/ he just admitted that he hadn t been taking them. he has gotting on me every day for 2 weeks or more. im disable so im in bed most of the time.