I need motivation

Because riding 500 miles in 6 days is clearly not enough to make me train. 

To be anywhere ready I should be riding 100+ miles weekly...and I'm averaging 40. I just get bored. 

Houston isn't the most biker friendly area so I'm stuck riding the same trails over and over. Its repetitive. 

Any suggestions? What has helped you stay motivated and push you along on long runs or bike rides?