I wear these on-ear headphones, after a few hours they really start to hurt my ears with the pressure they apply. i wear them for work, so i just ignore the pain and keep them on for hours. is there any long term damage im risking by doing this?

Are they to protect your ears from sounds or are you listening to them. I would suggest you get you hearing tested as if listening at high volume can damage ears even when young. If for hear protection and provided by work as for a better fitting set

You should change to a different headphone which is more comfortable. Chronic pain leads to different issues and it can affect your productivity on the job.