Did you run plain water through the pot before fertilizing? That looks like fertilizer burn but the peaty potting mix looks bone dry.

You can't overpot. That's nonsense. You can move to a big pot with poor water drainage, though. Overpotting is a soil problem, not a pot size problem. I'm wondering if you were careful about fertilization. Could be looking at fertilizer burn. Same appearance on all three plants in the same pot. So the same thing happened to all of them. Nitrogen heavy is good. Too much is bad.

I didn’t run water through it first. Is there anything I can do to help it?

Other than watering before fertilizing next time?

If it's fertilizer burn, what you need to do right now is run a LOT of water through it. Flush it out. How much fertilizer did you use?

Thank you for the help @daninthedirt I flushed it out and it’s back to growing like crazy!