Is lip balm that you put on your dry lips a barrier for water during ghusul? I put some on my lips around 40 minutes before doing ghusul. I didn't think much about it until after doing the ghusul.

If it is considered a barrier during ghusul, is it enough if I washed my lips carefully afterwards with the intention of it being part of my ghusul or do I have to redo my ghusul completely?

I can not judge this.
You are the only person who can judge it.
If it has a layer that isolates the water from the lips, then you have to wipe it before performing Ghusl.
You also have to do so, if you are in doubt.
Any how, if it is, then only washing the lips is not sufficient. You have to wash the entire body after washing the lips.