Tired... so tired

I am so tired of living with Anxiety and panic.  I am literally tired.  Trying to keep the anxiety and panic in check is so hard.  From the moment I wake up untll I am finally able to fall asleep my mind is always on alert.  If I have a twing, pain or just feel tired, my mind grabs onto the feeling and then I begin to obess about it and what it can possibly mean.  Am I going to have a heart attack, stroke, is my blood sugar low and I am going to go into a coma?  I know none of these are it but my mind just can't stop.  
It gets so bad that I have driven to work and then turned around and called in because i just couldn't walk in due to my anxiety/panic and as soon as I am half-way home, I am fine.  I've had discussions with my supervisor regarding it and if I don't learn to get it under control, I will have to file for FMLA or I may even get put on "coaching" or worse lose my job if I miss too much.  Well that adds more pressure but it makes me have to squelch the feelings and suck it up.  However, it is really hard to focus and I have to rely on my lorazapam more to get me through the day.  
On top of it all I am just tired of not living.  I watch my friends and family and they can have fun and relax but I can't as I am so focused on any sensations in my body.  I am jealous of them and get depressed because I feel left out but when they do invite me, I decline as I am too afraid to go somewhere in case I have an attack and can't get to a safe place.  Like tonite, it is a Saturday and instead of going to see a band that I have been wanting to see, I am sitting here at home alone on the couch typing this.   
 
Sometimes I feel like I am crazy.  I hate myself, my life and feel worthless.