Sorry to hear your problem.
If you cannot locate a replacement loom, the best way to repair the existing loom is to remove the burnt out one and lay it out. Don't try and replace wire for wire on the bike as you may miss damage that will cause another short! Unwind the loom tape that holds it all together. Where the loom 'branches' in different directions, use cable ties or string to secure in bundles (if you don't, it will never fit you bike again!). One wire at a time, cut out the damaged section and solder the new wire to the loom wire and then cover the joint with heat shrink. Try not to have all the connections at the same point in the loom; try and stagger them. With the loom laid out, it is easier to check the multiblocks. Once all the damage has been removed, use loom tape or a good quality electrical tape to cover the loom again. Do not wind it too tight but it must be secure.
Also, use different coloured wires if possible and make a note of it on the wiring diagram. If you use the same colour for all wires, tracing faults in months or years to come will be difficult.
This is the method that I use, and I used to do this for a job. Just take your time, go careful and if you are not sure, take photos to refer to later.
When you refit the loom pay attention to the routing making sure that there are no 'crush' points or places where the loom is pulling. Don't use tape to attach the loom to the frame etc if you can help it as it may loosen with heat and you new loom might slip and dangle onto the exhaust!

I would also go very careful using pressure washers, as they force water into places that need to stay dry ie switches, oil seals and bearings.

Good luck,
Eddie.