The final touch to your dough just prior to entering the oven is one of those moments that gives the inexperienced home baker performance anxiety. Understandable really, since many a nice loaf has been made to appear pretty average on account of the slashes.
Slashing is a bit like engraving or Japanese ink art on silk. Once you’ve executed it you can’t change it. It’s there for everyone to see, good, bad or ugly! There’s no fixing it, you just have to live with it.