Why doesn't anyone want to hire big people?

You may want to contact the vocational rehab. agency of your state, they may be able to assist you in finding employment (may being the operative word):

http://www.tennessee.gov/humanserv/rehab/vreligib.html

 Scotty's response was the best yet.  There are many programs out there for job hunters, from placement assistance to education assistance.  

http://www.tn.gov/labor-wfd/