I'm sorry to hear that this problem hasn't cleared up yet! It does sound like this might be a recurrent infection of the scalp. The crusty drainage that you describe would be consistent with that, as would the swollen glands at the base of your neck, which would be lymph nodes which are activated and trying to fight off the infection.
You definitely should go back to see your primary care doctor
about this issue right away. You may need another antibiotic to clear up the infection. If you had an unpleasant reaction to the last antibiotic that you were on, then you should mention this to your doctor, because they will be able to suggest a different antibiotic this time.
It is also worth thinking a bit about why this problem keeps coming back. Sometimes, for example, recurrent scalp infections occur because of an underlying inflammatory condition of the scalp, such as seborrheic dermatitis, psoriasis
, or an allergic reaction, which leads to skin breakdown and allows bacteria to invaded and set up the infection. Your primary care doctor will be able to help you think through this and determine if there is an underlying condition to treat.