clomid will fuck all to hell with your emotions. it is from the quick change in hormones - people will say it is estrogen - but that is bullshit - it is from the change of things and largely the huge change in LH and TSH.
if you are prone to depression, be very careful to be aware of your moods and know that they are only from the drugs.
and like spent said, the 300 is a high amount and kills - just do that one day, then down from there. I even found a week at 100 tough - but it stops feeling gross once you are all done with the stuff - during the hormonal times your skin will be crazy, but arimidex well help (helped me at least).
and like spent said, the longer you stay on something, and the more it shuts it down, the harder the comeback is - fina shuts you down hard - not sure how or why it seems to do it so much worse...