Lump on left side of head 2 cm behind ear. there for 2 months. if i apply pressure i can kind of flatten it out. had a ear infection 2months ago. 13yr?

Lymph node: Likely a post auricular lymph node, which often increases is size with local infections mostly skin and some viruses. Most of these are very tiny and lie over a bone called the mastoid. Have your doctor confirm this and continue to follow it until it is getting smaller.

Reactive node: Most likely this is a reactive lymph node from the ear infection.These can take a long time to resolve. You dont mention if there is a tenderness to the lump. Either way I would have it evaluated by your PCP or an ENT as a baseline. Thanks for consulting with Healthtap. :)

Need more info: Never the less this could be a a swollen lymph node or a cyst. You need to see your family physician to help make a diagnosis. If the "lump" is either of the two it should be a simple matter to remedy.