Put a delay in your repeat loop. That will absolutely spam the crap out of the light turn off service without it. It executes extreemly fast.
Actually, at first I thought you were using it because the communication to your light is bad. But now I realise it is just a really bad way to do things. There is no call for a loop in an automation like this. It should be state driven.
Have a look at this example:
Also it is bad practice to trigger automations manually from other automations. If you need to re-use a set of actions often then write a script and call that from each automation instead.