After falling on my right rib cage, tearing muscle tissue, I was ...

After falling on my right rib cage, tearing muscle tissue, I was precribed a 5mg dose- 1-3 times daily. Usually, I only needed to take one during the night, when the pain was worst. (Took ibuprofen during the day -due to the dizziness, drowsiness effects of flexeril). However, I noted that each morning after I took the flexeril - I woke up like "a bear with a sore head" to quote my wife's phrase. Free -floating hostility, irritabililty - snapping at every minor thing and every one. The effects sometimes taking the whole morning to wear off. Has anyone else noticed such 'psychological' side effects? I am sure they were attached to the flexeril, since once I'd stopped taking it, the 'bearishness' and chronic distemper creased. Note: I have been historically a 'drug-sensitive' person, and perhaps even at the 5 mg dose, I was OD'ing. That is one theory anyway.