Is there a way to change my TV remote’s frequency to stop it affecting my LED lights?

Unfortunately, there's not much that can be done since the TV remote's frequency is likely fixed. It seems that your LED lights might be using the same IR signals as your TV, probably because the manufacturers decided to keep things simple. One practical workaround is to cover the IR receiver on your LEDs with some tape when you're using the remote, that way they won't respond to it.

I doubt there's a way to change the frequency. The IR signals are set by design and without some serious modification to the remote or LEDs, you're pretty much stuck with the interference.

The easiest solution is to just get rid of one of them! Seriously, if you're having this much trouble, you might want to consider what works best for you—either your TV or the LEDs.