There's really no easy answer to your question. It completely depends on how deep the cuts are and it also depends on the type of skin you have. It usually takes a couple of months until they fade (of course depending on the depth of the cuts) and it can take up to 2 years for them to disappear or at least fade properly. However, if you have shitty skin (like me) they might stay visible for way longer than that.
Anyways, if you ever need anybody to talk to, you can message me. ;)