Your sed rate or (ESR) can be high with any cause of inflammation such as Rheumatoid arthritis, anemia, lupus, pregnancy, etc. Do you have a sore throat? Have you had your throat checked for a strep infection? You could also perhaps have mono if you had a sore throat, swollen glands and high fever, fatigue etc. A lot of things will cause high ESR and swollen glands. What other symptoms do you have?
I also had a very sore neck and it the tissue felt tender to touch. Turns out I had what is called a gorder and gravesdisease (hyperthyroidism). I had to have my thyroid gland removed. If you have not had your thyroid gland check it my me worth a shot. I hope whatever it is you find out soon and get to feeling better. Good luck!