I Have A Gland That Is Swollen And Has Been

I have a gland that is swollen and has been on and off for the last 2.5 years. I had antibiotics, but they did not help much. It is on the left side and I also had surgery near there too about 3 years ago. Every once in awhile it will start to feel uncomfortable. I have allergies and somewhat frequent colds because I work in a preschool, but I am worried it could be more than just a swollen gland from allergies. I never had problems with this before.

Thanks
Melissa