Welcome to the forum. It is generally better to only introduce yourself here and post vehicle-specific problems in the appropriate subforum for that vehicle so more fellow owners see the topic.
Trouble going under a load makes me wonder if your fuel pressure is low, so would check that in both engine idle state and while revving it, but before that I would hook up a scan tool and look for OBD2 trouble codes and some realtime data like the long term fuel trims, but see below, low electrical system voltage can cause the fuel pump not to perform properly, as well as cause misfires from spark plugs not firing, so checking the electrical system voltage is what I'd do first, then the scan tool second if nothing looks wrong with the electrical system.
Back lights stopped working, I would ignore for time time being unless it relates to what I write next.
Not starting, the idling rough, then losing power and especially the dash starts to go crazy is typical of low electrical system voltage, so it is likely your alternator is bad or the battery is very bad (probably a shorted cell to pull voltage down that much if the alternator is still working okay).
You could hook a battery charger up to the battery and see if it runs better after that, but before starting it, after the charger is disconnected for a few minutes, see what the rest state voltage is on the battery, should be pretty near 12.6V. If it is closer to 10.4V you have a shorted cell in the battery, assuming you left the charger on long enough to charge it otherwise.
If it stays near 12.6V, starts the vehicle fine, but then the longer it runs, the lower the voltage drops (should be around 14.4V with engine running), it is likely the alternator, assuming you don't have battery clamp or clamp wire corrosion causing inadequate power delivery but corrosion issues would be more apparent trying to start it than if it starts fine but then inadequate voltage drop later.
I don't know your familiarity with the resources available but many local auto parts stores will do a rudimentary alternator or battery test for free, or pull OBD2 codes but not realtime scan tool data. Generally to do work on older vehicle electrical systems you at least need a multimeter, but the fuel pressure can be checked with a (free) loaner tool from many auto parts stores.
