degenerative arthritis

I was told I have degenerative arthritis and there is mild apophyseal joint sclerosis in the lower lumbar spine, I don't know what this all means, but I have a very uncomfortable feeling in the middle of my back when I sit back against anything, it feels like my spine is touching the back of the chair and when I lay down there feels like a lump in the middle of my back on the left side of my spine. I really don't sit back against anything anymore I find myself leaning forward or sideways. Can you give my any idea of what this is and what I can do to improve it.