Hi and welcome,
Your question has landed in the MS community but it would be a huge leap to be thinking MS could be the most likely explanation, i would strongly suggest you see your doctor if you haven't already, 12 weeks straight is a long time to have a headache or migraine!
Keep in mind you have been dealing with depression, anxiety and paranoia so It really wouldn't be in your best interest to give a lay persons opinion on whether or not it sounds serious or not, there could be a connection to your mental health situation but honestly your better off seeing your dr and probably getting some tests done...
Sorry i couldn't be of more help.......JJ