Sore elbow in the joint, feels like what people describe as arthritis. Been feeling this way for about four months, very painful?

See pcp. Get some xrays elbow DJD uncommon not much surgical to offer start with nsaids rest keep it gently moving elbows love to get stiff.
See your doctor. Several possible causes of sore joints such as injury, infection, osteoarthritis, inflammatory arthritis (like ra). Best to have x-ray films to start with but this most often does not show evidence of inflammatory arthritis unless there is already damage to joint. Soft tissues injuries often respond well to physical therapy. Can try nsaids like ibuprofen, naproxen, Mobic (meloxicam) but always take with food.