Welcome to the forum.
If the camera still record good video you are good, but as the LCD are on the way out the rest of the camera will probably follow soon.
The screen should turn off after a little while, if you have disabled this and driven for 2 years with the LCD always on, then thats probably why the LCD are acting up.
2 years is also where i would start to worry about memory card, it will not be the cause of this LCD problem, but i would keep a close eye on the memory cards performance.