Unexplained neck pain and swelling right side neck

[Hurtmyneck]

Hi,for 6 months I have had swelling or extra muscle in my right side of my neck,pain and spasms.the pain and muscle tightness is in the whole right side of my neck and goes across the trap and into my shoulder.the swelling or extra muscles is in the front and side of the right side of neck and a bit in the trap.i don’t even know how I hurt it,I just woke up in pain one day.i have been to a couple of doctors,I had a neck ct scan done and everything was ok.doctors have also done some blood tests and again all good.i had an ultrasound done on shoulder and it said no rotor cuff tear. Anti-inflammatory help alot but don’t fix anything and Iv been going to Physiotherapy and they help with taking the tension and tightness out of the muscles,but still in pain just about everyday.its been at least  6 months now and I don’t think I’ve just pulled a muscles or something now.i don’t know what to do,it’s seriously affecting my life.i have noticed it gets a lot worse when I drink alcohol or lay in bed.please any help would be most appreciated