Not necessarily the cause of your problem but that's a lot of motor for a 60A ESC. Most offroad use would recommend at least a 120 or 150A ESC for a 5.5T. The 60A is usually bundled with a 9T motor like
here
My Hobbywing Xtreme Stock ESC is 60A and its limit is 8.5T and even that is stretching a point on a 4WD but in a 2WD like your 22 should not be too bad.
However back to your problem, it does sound like a short circuit in the system somewhere. The FET's in your speedo can fail short circuit and this sounds quite likely. Also shorting a Lipo is not great and you should watch for swelling of the packs, if they are swelling, leave them in a metal box or outside where they cannot cause any damage if the overheat and possibly catch fire. Were all the electrics new or second hand?
Can you post pics of your setup so we can see the wiring you have and check all is wired as it should be. With saddle packs they should be in series so one batteries black connector is connected to the other batteries red connector with what is called a link wire, you can see disconnected in this picture of a 22.
Check you have not accidentally shorted any connectors you might have in line (Deans etc). You probably can't check any more with the speedo as it is toast I suspect and will need to borrow/buy a new one to go further.
Post back and see what we can come up with.