I've got a lump/swallon gland on back of roof of mouth unsure what it can be? I've had sore throat from sinus drainage, now a dry cough\ itcy throat?

Lymph node. This may well be an enlarged lymph node responding to the infection, but without seeing it this would only be a guess. The best thing for you to do is to let a doctor take a look at this and make sure it is not an abscess, a tumor, or something else severe. Good luck.