don't mess with pharma's just yet breh, that would be counterproductive to your cause in the long run.
a good meditation and breathing regiment will help you immensely. practice a meditation of calming the mind, stilling the mind, and/or having a single-point focus on a person/place/object/event/idea.
dont get frustrated if your thoughts are all over the place at first. remember mental exercises are just like physical exercises, the more you practice the better you get at it.
for the breathing read this:
http://www.arfalpha.com/ScienceOfBreath/ScienceOfBreath.pdf
be sure to incorporate the breathing exercises into your meditations.
all of these things are good practices to strengthen the mind, however, you should understand all of this will begin and end with your
personal willpower. it'll ultimately come down to whether or not you have the mental stamina to consistently make yourself focus at will, and whether you can sustain the practice.
just keep at it and you'll eventually get there. you only lose if you quit.