I am experiencing severe neck pain and neck lump or bulge. arm pain also been experiencing for several months. no accident what could be wrong?

Neck: Sounds like degenerative cervical spine disease. Get CT or MRI scan

Difficult to know: Without a physical exam it is difficult to know if what you are experiencing is due to a pinched nerve and subsequent muscle spasm, a lipoma pressing on a nerve, or herniated disc in your cervical spine, among others. The arm pain may be referred from the neck or it could be a separate issue -good physical exam by an MD or DO should be able to better differentiate what may be going on, so see Dr!