My rear wheel becomes extremely out of true every two or three weeks, riding an average of 100 miles a week. The roads i ride on mostly are poor quality with bumps, potholes, manholes, tracks, and everything else to knock the wheel out of true. Also i am carrying some loads, but nothing over 15-20lbs on a daily basis.

Today i didn't even want to risk riding in with the wheel like that because it makes the ride very unstable, especially when descending with a lot of speed.
I am getting tired of constantly taking it to the shop to have it trued. It is still on the one year fee maintenance plan, so it isn't the cost, it is just becoming a pain.

Could the wheel be shot if i have to true it this often?

Should i just get some new wheels?