Tired Of Being Like This Too Paranoid To Concentrate?

I am so tired of being like this. I cannot think, and cannot keep a job because my anxiety is too great and I cannot focus my mind. It is like I am constantly spaced out or in another dimension or something and somehow I feel I need to be able to think on the spot instead of constantly in fear of the worst which only seems to make the worst come true. I have been battling depression for several years however despite going to therapy and being on Wellbutrin I just don't feel right. It is as though my brain is in constant overload and off in some wild tangent. I have often thought that maybe perhaps I am bipolar or something since I am in constant overload. I am also very creative, which I like. However at the same time it isolates me since I am often lost in my mind and at the same time it is as though I have too many things running through my mind to actually create good art. I have all these thoughts about wanting to die, and couruption of society etc and how from the very beginning I was bound to fail in the real world once I graduated. I know that I am setting up a lot of my failure because when I think the worst about my job etc I am bound to make even more mistakes and my concentration becomes like a train wreck. I want to be able to feel normal and stop over analyzing everything. I want to be able to have fun and live in the moment without 1 trillion things running through my head. I also have a habit to self harm and have punched myself in the face before really hard resulting in black eyes. Besides Wellbutrin I also take 50mg of serroquel at night time to help me sleep. Would this medication at a higher dose get rid of my obsessive/ paranoid behavior? I know for bipolar a much higher dose of serroquel is used usually in the 200 to 400mg a day range. Will this, or anything else quiet off my overactive mind? I really really want to relax and stop taking things so seriously and be able to be social/ go with the flow. I want to be able to watch a movie without being overloaded with thoughts and opinions and perhaps even become a bit complacent so that I actually hang onto a job when I have the opportunity. I just want to feel normal, whatever that is and enjoy life. I recently started working at a print shop as a graphic designer and they let me go after my 5th day because I couldn't concentrate and measure accurately. Although this is a very very hard set back I have always had trouble with extremely precise measurements especially with things that are like a 32nd or 64th of an inch. I'm hoping to find something perhaps working for a magazine or doing posters/ brocures etc but not technical drafting. Or perhaps I will go more into web design since I am aware of coding/ web standards etc. But I need help. Something is definitely wrong. I know it is not healthy to be overwhelmed and paranoid 24/7. **** I'm only 23 and feel like I have not even lived whatsoever. I did go to college etc but I never really "lived" and had fun. I can not spend another 60 years in this paranoid state. Can anyone suggest any medication that will help me to relax and not over think everything? anxiety and depression is no fun and it seems the only thing any of the ssri's have done was to give me more energy which only seems to make me more paranoid. I have to be able to function.