Facial swelling taking very long to subside after wisdom teeth extraction... it has been 3 months already and its only maybe 50% back to normal?

Must see the surgeon. This is highly unusual and probably is being caused by an infection and possibly a fracture of the jaw. A follow up visit with the surgeon and new X-ray to determine the cause is important. If a definitive diagnosis is not obtained seek a 2nd opinion but do not delay.
Unusual. This is very unusual and could signify a serious problem. Usually swelling will be accompanied by pain and/or fever. I would suggest seeing the doctor who removed the teeth for an evaluation.