Head neck cancer is quite an agressive disease. A small mobile swelling with no increase in size for last 6 months is unlikely to be cancerous. It could be secondary to whatever is causing your nose bleed, post nasal drip and phlegm in throat. Or it could be a reaction to recurrent colds or a scalp problem.
Next Steps
You need a thorough examination to narrow down the cause. You may also need imaging, depending on your examination findings.