The fuse will have something written on it near the ends. This will include the voltage rating and the current. It may be encoded. See if you can read what it says and the value may become obvious. If not, post it here and we can probably interpret it.
That fuse has wires soldered to the ends of it. If you can't get hold of one of these (they're rarer than the type without leads) then get one of a similar size and solder (carefully) some wires onto the ends of it.
Do you know how to solder? Do you have a soldering iron?
It is quite possible that the fault is more than just the fuse. If it blows immediately after you apply power, then something more than just the fuse is wrong.
Yes, the capacitor is dangerous. Even after discharging then, they can develop a high voltage across them again and it can bite. Keep well away from it and respect the fact that if fully charged you don't want to get any part of yourself (or anything you're holding) within several inches of it.
If you're discharging it with a screwdriver that is clipped to earth (or similar) then I would add a 500mm length of PVC tube as an extension handle.
Not sure about you, but I'm pretty sure I only have one life.