Save your Lemmy homepage as a shortcut on your Home Screen, move your Reddit app and replace it with your Lemmy shortcut.
I just opened Reddit 5x today and had to figure out how to train myself not to use it. This seemed to help me, I hope it helps others too.
Stay strong brothers and sisters. Remember, the more we post, the better it gets.
I ended up uninstalling reddit, because I opened it too much. Then, as you said, I moved the lemmy icon to where reddit used to be.