Welcome to Healthcare Magic.
Well you think your this condition might be because of this low blood pressure. The answer is No. 90/60 is not that low blood pressure which could be the cause of such serious symptoms. in our center of heart failure
patients, every next patient have bp of 90/60 and they are all are doing fine. just take enough drinks and food this BP problem will be solved.
Now coming to head injury
and headache. The reason for these all above symptoms can either be MS or Head injury. We cant differentiate this unless we do CT. CT will tell us if there is any damaged occurred in your brain (esp hemorrhage) then you should be treated for that condition. If no damaged has occurred then it might be MS. So lets just wait for the CT results. it all upto CT now.
Get well soon. and take care of yourself.