I have also been taking Doxycycline Monohydrate 100mg everyday for three months.
I have not used needles on myself to try and remove it. What I was trying to say is that I have not had any needles in me other when i go to get my shots for vaccines.
looks like a lymphocele
Further to what Kim has stated, this is from a reliable medical source: . " Lymphocele can form on the penis and occurs in sexually active males. Lymphocele of the penis is generally harmless and does not require any treatment. The condition develops due to vigorous masturbation or prolonged, intense sex sessions and is characterised by the presence of what looks like a horizontal or vertical swollen cord. It results in the temporary blockage of lymph channels in the penis. "
over masturbation can also cause them u could try gently trying to rub the lump down but usually they do go away by themselves