Some cables can be fixed, some can't
It's not easy to answer your question on the net, without seeing the cords. Especially since you seem to have a short fuse.
Usually, it's easier to buy a GOOD new one.
It may be more hassle fixing the old one, if you don't have someone there to help you fix it.
Another thing to look at, is the connection, where the cord plugs into the guitar, or amp.
These can get loose too.
If you can tighten the nut on the OUTside of the amp, do that, slowly and carefully.
I wouldn't touch the inside of amp, if I were you, there is a lot of voltage in there.
But you can at least tighten up the nut on the jack plate, on the guitar.
The cable inside the jack plate can go bad too.
It's easy to show, hard to explain.