My 35 Year Old Son Has A Large Swollen Area

My 35 year old son has a large swollen area below his jaw on the left side of his neck. It appears to be a lymph node to me. The size fluctuates -- larger after sleeping, a bit smaller after showering, sore to the touch. He has suffered from a series of bad respiratory infections which never seen to go away completely, and he is a smoker. He has no primary physician and is reluctant to go to the ER. There is a shortage of Urgent Care options. Any advice? Thank you/