I can't give you an exact answer but from what I am reading from your post, it sounds like the lump is at the top of the muscle where the tendons would be that attach the muscle to the bone. Tendons can definitely feel lumpy. I know I can feel that on the tendons behind my knees - and probably could in the same spot you are talking about if I really wanted to feel it (I don't so it doesn't kick start my HA!) I can tell you that if you have to "press down" into anything then it is probably supposed to be there (that and you will most definitely find something - even something normal). You probably have some tight muscles (do you workout? even if you don't, you have anxiety so that automatically means you get muscle tightness somewhere in your body whether you know it or not!). Although my HA centers on lumps and things like that, I can tell you, if it was your "worst fears", you would have alot more going on with yourself than what you just described. Anxiety is the heart of the problem. It is not the "lump" you feel that you need to address, it is the anxiety - also (I have been told this so many times) our bodies are asymmetrical and they are naturally lumpy and noisy and if you poke around, you will always find something - stop poking around! Hope this helps.