I work out at the gym regularly, but I think I may have pulled a muscle in my neck. I first noticed it while masturbating; near climax, I felt an extreme pain in my neck and had to stop. First I thought it was just sex headache, but I still feel slight pain every day for the past week. If I try to lift anything too heavy, or have sex or masturbate, the pain comes back intense. Is this just a pulled neck muscle that will heal soon, or is it something else?