Lump at the back of my neck

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I noticed a lump at the back of my neck. I noticed it few years ago. One of my mom's friend told me it was a lymph node. It is not visible. You can't feel it if you are looking straight. If you tilt your head down and to the left you can feel it. If you tilt your head up and to the right you can't feel it. It looks like a smooth surface. It is located at the upper left just below the hair and near the spine. It didn't change it size tho sometimes you can't almost feel it. It really bothers me and I'm scared. I'm just 20 and they told me i shouldn't worry about it and im just being paranoid. I hope someone could answer me and btw it's not painful tho sometimes my shoulder blades feels like it's sore